A narrow beam of white light can be split up into different colours by a glass prism. The correct explanation is that

A.

white light is an electromagnetic wave

B.

the prism has all the colours of the white light

C.

white light has undergone total internal reflection in the prism

D.

different colours of white light travel with different speeds in glass

E.

white ligth consist of yellow, green and red colours

Correct answer is D

No explanation has been provided for this answer.