Fact 1: Bacteria cause food poisoning.

Fact 2: Food poisoning is a serious illness.

Given the two facts above, answer the question "what does bacteria cause?" with the following options: 
- loss of h2o
 - harmful substances
 - Pollution
 - serious illness
 - increase in oxygen
 - carbon
 - Deoxyribonucleicacid
 - symptoms


 

    serious illness     