You are presented with the question "what can be used to kill existing microorganisms in food?" and the following answer choices: 
- chemical changes
 - Dehydration
 - deoxyribonucleic acid
 - bacteria
 - an electron microscope
 - hydration
 - electromagnetic energy
 - single-celled organisms

Now knowing that irradiating food can be used to kill existing microorganisms in the food and irradiation causes chemical changes, choose the best answer.


 

 chemical changes        