Fact 1: Freezing causes a solid to form.

Fact 2: Ice, on the other hand, is a solid.

Given the two facts above, answer the question "What causes ice to form?" with the following options: 
- liquid
 - Metling snow
 - freezing
 - water
 - Condensation
 - burning
 - melting
 - heat


 

   freezing      