Fact 1: Microorganisms cause food to spoil.

Fact 2: Food poisoning occurs when spoiled food is eaten.

Given the two facts above, answer the question "What causes food poisoning?" with the following options: 
- one celled organisms
 - water vapor
 - microorganisms
 - influenza
 - Pesticides
 - harmful substances
 - oxygen
 - poison


 

   microorganisms      