You are presented with the question "What do prisms do to light?" and the following answer choices: 
- focusing a lens
 - Refract it
 - Reflect it
 - protect them
 - Absorb it
 - observe it
 - It expands
 - Diffraction

Now knowing that glass cause refraction of light and prisms are round pieces of glass, choose the best answer.


 

  Refract it       