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

Fact 2: Irradiation kills microorganisms that spoil food.

Given the two facts above, answer the question "what can be used to extend the shelf life of food" with the following options: 
- Cooking
 - Enzymes
 - rays or beams
 - irradiation
 - leaving food at room temperature
 - Dehydration
 - eating food
 - grinding food


 

    irradiation     