Fact 1: Killing microorganisms in food can be used to extend the shelf life of that food.

Fact 2: Sterilization kills all viable microorganisms.

Given the two facts above, answer the question "What can be used to extend the shelf life of that food?" with the following options: 
- sterilization
 - Enzymes
 - poison
 - chemical changes
 - hybridization
 - gasoline
 - rays or beams
 - Cooking


 

 sterilization        