The correct answer is Only b.

• Mica is used in the iron for pressing clothes since Mica is a good conductor of heat.
• Mica is a bad conductor of electricity and can endure high temperatures.
• They are heat tolerant, insulating and dielectric.
• Because of these properties they are used in electrical appliances.
• Hence correct answer is Only b.

• Mica is a naturally occurring element.
• It is optically flat, translucent, elastic in nature.
• Its composition is silicate, aluminium, potassium, manganese, water and iron.
• It contains the highest amount of silica and so is the most preferred mineral in industries and in other personal applications.
• Mica is a bad conductor of electricity and can endure high temperatures.   
• Uses of mica mineral:
  • Mica is a non-toxic mineral.
  • It is one of the important ingredients in makeup and various cosmetics.
  • It gives a shimmery effect and adds sparkle.
  • It gives a glowing effect with a natural finish.
  • There are no side effects and suits for all types of skin.
• Uses of mica powder:
  • To have an attractive background for your scrapbook mix water and mica powder and spray it on the scrapbook.
  • Mix in oil paint to give extra painting effects. 
• Uses of mica capacitor:
  • These are also called silver mica capacitors.
  • They offer stability, high precision and reliability.
  • There are various two types of mica capacitors with different applications like – coupling circuits, cable TV amplifiers, resonance circuits, defence electronics, time constant circuits etc.
• Uses of mica sheet:
  • Mica can be made into thin sheets. They are heat tolerant, insulating and dielectric. Because of these properties they are used in electrical appliances. They are used in control devices, heating devices, neon lights and other lighting equipments.