Fact 1: Glass cause refraction of light.

Fact 2: Prisms are round pieces of glass.

Given the two facts above, answer the question "What do prisms do to light?" with the following options: 
- focusing a lens
 - Refract it
 - Reflect it
 - protect them
 - Absorb it
 - observe it
 - It expands
 - Diffraction


 

  Refract it       