Fact 1: Water causes refraction of light.

Fact 2: Water includes all liquids.

Given the two facts above, answer the question "What causes the refraction of light?" with the following options: 
- focusing a lens
 - Chemical energy
 - fossil fuels
 - all liquids
 - a solute
 - chemical changes
 - an electron lens
 - squids


 

    all liquids     