White light while passing through a glass prism breaks up into light of different colours because

• Correct answer
  A

  refractive index of glass for different colours of light is different
• B

  glass prism absorbs white light and emits lights of several colours in different directions
• C

  of total internal reflection of white light on surfaces of the prism
• D

  of the interference of different colours inside the prism

Hence, the correct answer is option: 'A'.