Fact 1: Heating an egg causes a chemical reaction in the egg.

Fact 2: Heat is very important in cooking.

Given the two facts above, answer the question "What causes a chemical reaction in an egg?" with the following options: 
- sugar
 - the water cycle
 - cooking
 - birds
 - tapeworms
 - courtship
 - burning
 - ovaries


 

   cooking      