InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Choose the correct statement(s) about colour of lathanoids:A. Colour of the ions may be attribued to the presence of f-electrons.B. `Lu^(3+), Yb^(2+), La^(3+), Ce^(3+)` are colourless.C. Absorption bands are narrow, probably because of excitation within f-level.D. Elements with (n) f electrons have a similar colour to those with (14-n)f electrons. |
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Answer» Correct Answer - A::B::C::D `Lu^(3+), YB^(2+) rarr 4f^(14)` `La^(3+), Ce^(4+) rarr 4f^(0)` |
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| 2. |
Select the species which is an oxidant?A. `Eu^(2+)`B. `Yb^(2+)`C. `Ce^(4+)`D. `Tb^(4+)` |
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Answer» Correct Answer - C::D `Ce^(4+) rarr Ce^(3+)` `Tb^(4+) rarr Tb^(3+)` |
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| 3. |
Statement-1 : Lanthanoid contraction is more important than actinoid contraction is more important than actinoid contraction. Statement-2 : Chemistry of elements surrounding the actinoids are much less known at the present time.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
| Answer» Correct Answer - A | |
| 4. |
Find the number of inner transition elements among those having following atomic numbers : 29, 59, 74, 95, 102, 104, 89, 57, 72. |
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Answer» Correct Answer - 3 59, 95, 102 are inner transition elements. |
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| 5. |
Identify the only paramagnetic species:A. `Ce^(4+)`B. `Yb^(2+)`C. `Lu^(3+)`D. `Nd^(3+)` |
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Answer» Correct Answer - D `Lu^(3+), Yb^(2+) rarr 4f^(14)`, `Ce^(4+) rarr 4f^(0)`, `Nd^(3+) rarr 4f^(3)` |
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| 6. |
Statement-1 : 5f orbitals resemble the 4f orbitals in their angular part of the wave-function. Statement-2 : 5f orbitals are not as buried as 4f orbitals and hence 5f electrons can participate in bonding to a far greater extent.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
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Answer» Correct Answer - B Both 5f and 4f have `l=3`, so angular part of wave function is similar. |
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| 7. |
The most common oxidation states of cerium areA. `+2` and `+4`B. `+3` and `+4`C. `+3` and `+5`D. `+2` and `+3` |
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Answer» Correct Answer - B |
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| 8. |
Which of the following ion is paramagneticA. `La^(3+)(Z=57)`B. `Lu^(3+)(Z=71)`C. `Yb^(2+)(Z=70)`D. `Sm^(3+)(Z=62)` |
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Answer» Correct Answer - D |
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| 9. |
Statement-1 : `Ce^(4+)` can oxidise water. statement-2 : `Ce^(4+)` is a good analytical reagent.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
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Answer» Correct Answer - B Oxidation of water is very slow so `Ce^(4+)` is a good, analytical reagent. |
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| 10. |
If outermost E.C. of Ce is `4f^(1) 5d^(1) 6s^(2)`, then select the incorrectly matched outermost E.C. of its various ions in ground state:A. `Ce^(2+) rarr 4f^(1) 5d^(1)`B. `Ce^(3+) rarr 4f^(1)`C. `Ce^(4+) rarr 4f^(0)`D. `Ce^(2+) rarr 4f^(2)` |
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Answer» Correct Answer - A `Ce^(2+) rarr 4f^(2)` |
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| 11. |
Strong yellow colour of `Ce^(4+)` solutions and blood red colour of `Sm^(2+)` solution arises due to :A. charge transfer from M to LB. charge transfer from L to MC. f-f spectraD. absorption in UV region |
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Answer» Correct Answer - B Intense colours are observed because of charge transfer spectra. |
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| 12. |
The separation of lanthanides by the ion exhange method is based onA. The solubility of the nitratesB. Size of the hydrated `M^(3+)` ionsC. Size of the unhydrated `M^(3+)` ionsD. Basicity of the hydroxides |
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Answer» Correct Answer - B |
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| 13. |
Ion with maximum number of unpaired electronsA. `Lu^(3+)`B. `Yb^(3+)`C. `Tm^(3+)`D. `Gd^(3+)` |
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Answer» Correct Answer - D |
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| 14. |
`UO_(2)^(2+)` is expected to have which shape?A. Angular, unstableB. Linear, stableC. Angular, stableD. Linear, unstable |
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Answer» Correct Answer - B `[O=U=O]^(2+)` is linear and stable. |
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| 15. |
Statement-1 : `Ce^(4+)` is more stable than `Ce^(3+)`. Statement-2 : `Ce^(4+)` has noble gas configuration.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
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Answer» Correct Answer - D `E^(@)((C^(4+))/(Ce^(3+))) = +1.74 V` |
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| 16. |
What factor make the separation of Lanthanides a formidable taskA. Similarity in ionic sizeB. Constant charge of + 3C. Small charge radius ratioD. All of these |
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Answer» Correct Answer - D |
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| 17. |
SRP values of lanthanides lies betweenA. `-2.2` to `-2.4 V`B. 4 to 2 VC. 1 to 5 VD. `0.1` to `-0.2 V` |
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Answer» Correct Answer - A |
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| 18. |
Statement-1 : Occasionally +2 and +4 oxidation states of lanthanides are obtained. Statement-2: Empty, half-filled or filled f-subshell are extra stable.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
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Answer» Correct Answer - A `+2` and `+4` oxidation state occur if `f^(0), f^(7), f^(14)` E.C. occur. |
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| 19. |
Consider the following statements (s) which of the following is false ?A. `Eu^(+2)` is a strong reducing agent (Z of Eu = 63)B. `Ce^(4+)` is a strong oxidising agent (Z of Ce = 58)C. Curium hs electronic configuration: `[Rn] 5f^(2) 6d^(1) 7s^(2)` (Z of Cm = 96)D. `Yb^(+2)` is an oxidising agent (Z of Yb = 70) |
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Answer» Correct Answer - D `Yb^(2+)` is an oxidising agent. |
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| 20. |
Select the correct statement(s) about chemical behavior of lanthanoids:A. `II^(nd)` I.E. are comparable with those of calcium.B. Earlier members of the series are quite reactive, similar of calcium.C. With increasing atomic number, they behave more like aluminium.D. The metals combine with hydrogen when gently heated in the gas. |
| Answer» Correct Answer - A::B::C::D | |
| 21. |
Knowing that the chemistry of lanthanoids (Ln) is dominated by its `+3` oxidation state, which of the following statement is incorrect?A. Ln(III) compounds are generally colourlessB. Ln(III) hydroxides are mainly basic in characterC. Because of the large size of the Ln(III) ions the bonding in its compounds is predominantly ionic in characterD. The ionic sizes of Ln(III) decrease in general with increasing atomic number |
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Answer» Correct Answer - A Ln (III) compounds are generally coloured. |
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| 22. |
Most common oxidation states of La and Ln respectively are :A. `+2, +2`B. `+3, +3`C. `+2, +3`D. `+2, +4` |
| Answer» Correct Answer - C | |
| 23. |
Knowing that the chemistry of lanthanoids (Ln) is dominated by its `+3` oxidation state, which of the following statement is incorrect?A. because of the large size of Ln (III) ions, the bonding in their compounds is predominatly ionic in character.B. the ionic size of Ln (III) decreases in general with increasing atomic numberC. Ln (III) compounds are generally colourlessD. Ln (III) hydroxides are mainly basic in character. |
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Answer» Correct Answer - C |
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| 24. |
Which lanthanoide compounds is used as a most powerful liquid lasers after dissolving it in selenium oxychlorideA. Cerium oxideB. Neodymium oxideC. Promethium sulphateD. Ceric sulphate |
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Answer» Correct Answer - B |
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| 25. |
Which one of the following pairs of elements is called chemmical twins because of their very similar chemical propertiesA. Mn and WB. Mo and TcC. Fe and ReD. Hf and Zr |
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Answer» Correct Answer - D |
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| 26. |
Which of the following exhibits only +3 oxidation state?A. AcB. PaC. UD. Th |
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Answer» Correct Answer - A Inner transition element belong to group 3. Ac has 3 electrons in `7s+6d`. |
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| 27. |
Which of the following ions will exhibit colour in aqueous solution ?A. `Sc^(3+)`B. `La^(3+)`C. `Ti^(3+)`D. `Lu^(3+)` |
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Answer» Correct Answer - C `Ti^(3+)` has one unpaired `e^(-)`. |
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| 28. |
Which sub shell is filled up progressively in actinoidsA. `1.4f`B. 5fC. 6dD. 7s |
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Answer» Correct Answer - B |
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| 29. |
Statement -1 : Actinoids are very difficult to study. Statement-2 : Actinoids are radioactive elements having very short half lives especially of later members of actinides.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is falseD. Statement-1 is False and Statement-2 is True. |
| Answer» Correct Answer - A | |
| 30. |
The atomic and ionic radii (`M^(3+)` ions) of Lanthanide elements decrease with increase in atomic number. This effect is calledA. Lanthanoid contractionB. Lanthanoid expansionC. Actinoid contractionD. Actionoid expansion |
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Answer» Correct Answer - A |
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| 31. |
Which lanthanide among the following can exhibit +4 oxidation state but only in oxides `(MO_(2))` ?A. PrB. NdC. TbD. Dy |
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Answer» Correct Answer - A::B::C::D `PrO_(2), NdO_(2), TbO_(2), DyO_(2)` |
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| 32. |
Best single use of lanthanide is :A. industrial manufacture of high voltage batteriesB. productions of alloy steels for plates and pipesC. productions of bullets, shell and lighter flintD. Ln oxides are used as phosphor in television screens and similar fluorescing surfaces. |
| Answer» Correct Answer - B | |
| 33. |
Ce is the first element of lanthanide series. What is the most suitable E.C. of `Ce^(3+)` ?A. `[Xe]4f^(1) 5d^(1) 6s^(2)`B. `[Xe] 4f^(2)`C. `[Xe] 4f^(1)`D. `[Xe]4f^(0)` |
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Answer» Correct Answer - C `Co: [Xe]4f^(1)5d^(1)6s^(2)` |
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| 34. |
Lanthanoid contraction is caused due to:A. the same effective nuclear charge from Ce to LuB. the imperfect shielding on outer electrons by 4f electrons from the nuclear chargeC. the appreciable shielding on outer electrons by 4f electrons from the nuclear chargeD. the appreciable shielding on outer electrons by 5d electrons from the nuclear charge |
| Answer» Correct Answer - B | |
| 35. |
The lanthanide contraction is responsible for the fact thatA. Zr and Y have about the same radiusB. Zr and Nb have similar oxidation stateC. Zr and Hf have about the same radiusD. Zr and Zn have the same oxidation state |
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Answer» Correct Answer - C |
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| 36. |
In the coinage metals (IB) group, the I.E decreases from Cu to Ag and the increases from Ag to Au this is attributed toA. Increased atomic sizeB. Increased ionic radiusC. Increased nuclear densityD. Lanthanuide contraction |
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Answer» Correct Answer - D |
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| 37. |
The number of unpaired electrons in gadolinium (Z=64) is :A. 2B. 6C. 8D. 3 |
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Answer» Correct Answer - C `4f^(7)5d^(1)` |
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| 38. |
Wood or cattle dung ash is used for cleaning cooking utensils in many parts of India. The statement that is not true for this ash is :A. it largely consists of metal oxides and silicates because non-metals during burning of the wood/dung cakesB. when added to water, it forms alkaline solution with `pH ~ 8` and above, which helps to remove oily substances from the untensilsC. several chemical components of ash remain undissolved as solids in water and these solids help in cleaning by providing scrubbing actionD. if left moist for a few hours in air, it slowly turns acidic because of oxidative decomposition |
| Answer» Correct Answer - D | |
| 39. |
Which elements among the Lanthanides has the smallest atomic radius ?A. CeriumB. LutetiumC. EuropiumD. Gadolinium |
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Answer» Correct Answer - B |
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| 40. |
Pair of ions which are having only one unpair electronA. `Ce^(3+), Yb^(3+)`B. `Eu^(3+), Tb^(3+)`C. `Pm^(3+), Sm^(3+)`D. `Dy^(3+), Tb^(3+)` |
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Answer» Correct Answer - A |
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| 41. |
The incorrect statement for lanthanides among the following statements is :A. 4f and 5d orbitals are so close in energy that it is very difficult to locate the exact position of electrons in lanthanidesB. Most common stable oxidation state is +3C. Tripositive lanthanide ions have characteristic colour depending on nature of group with which they combine to form compoundsD. Some lanthanides ions absorb colour either in infrared or ultraviolet region of electromagnetic spectrum |
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Answer» Correct Answer - D All but one `(Lu^(3+))`, lanthanide ions show absorptions in the visible of near UV region of the spectrum. |
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| 42. |
Lanthanides are separated best byA. Fractional crystallisationB. Solvent extractionC. Complex formation using EDTAD. Ion exchange resins |
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Answer» Correct Answer - D |
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| 43. |
Which of the following is the strongest baseA. `Sc(OH)_(3)`B. `La(OH)_(3)`C. `Lu(OH)_(3)`D. `Yb(OH)` |
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Answer» Correct Answer - B |
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| 44. |
The inner transition elements are the elements which the added electrons go toA. (n-1)d-orbitalsB. (n-2)f-orbitalsC. (n-1)d-orbitals and (n-1)f-orbitalsD. (n-1)d-orbitals and ns orbitals |
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Answer» Correct Answer - B |
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| 45. |
Which of the following is not the configuration of lanthanoidA. `[Xe]4f^(10).6s^(2)`B. `[Xe]4f^(1)5d^(1).6s^(2)`C. `[Xe]4f^(14)5d^(10)6s^(1)`D. `[Xe]4f^(7)5d^(1)6s^(2)` |
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Answer» Correct Answer - C |
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| 46. |
The most common oxidation states of cerium areA. `+2, +4`B. `+3, +4`C. `+3, +5`D. `+2, +3` |
| Answer» Correct Answer - B | |
| 47. |
The expected electronic configuration of cerium isA. `[Xe]4f^(0)5d^(1)6s^(2)`B. `[Xe]4f^(1)5d^(1)6s^(2)`C. `[Xe]4f^(2)5d^(0)6s^(2)`D. Both 2 and 3 |
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Answer» Correct Answer - B |
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| 48. |
Cerium `(Z= 58)` is an important nember of the lanthanoids . Which of the following statements about cerium is incorrect ?A. The + 3 oxidation state of cerium is more stable than the + 4 oxidation state.B. The common oxidation states of cerium are + 3 and + 4C. Cerium (IV) acts as an oxidizing agentD. The + 4 oxidation state of cerium is not known in solutios. |
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Answer» Correct Answer - D |
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| 49. |
Lanthanoids areA. 14 elements in the seventh period (At. No. 90 to 103) that are filling 5f sublevel.B. 14 elements in the sixth period (At. No. 58 to 71) that are filling 4f sublevel.C. 14 elements in the seventh period (AT. No. 58 to 71) that are filling 4f sublevel.D. 14 elements in the sixth period (AT. No. 90 to 103) |
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Answer» Correct Answer - B |
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| 50. |
Whether f-orbitals are filled or empty has little effect on :A. chemical properties (common)B. colour of ionsC. magnetic properties of lanthanide ionsD. all of the above |
| Answer» Correct Answer - A | |