Four students A, B, C and D noted the initial colour of the solutions in beakers I, II, III and IV. After inserting zinc rods in each solution and leaving it undisturbed for two hours, noted the colour of each solution again.They recorded their observations in the form of a table given below: Student Colour of the solution I II III IV A Initial Final Colourless Colourless Colourless Colourless Light green Colourless Blue Colourless B Initial Final Colourless Colourless Light yellow Colourless Light green Light green Blue Colourless C Initial Final Colourless Light blue Colourless Colourless Light green Colourless Blue Light blue D Initial Final Light green Colourless Colourless Colourless Light green Dark green Blue Colourless Which student noted the colour change in all the four beakers correctly?