Fact 1: Bacteria can cause people to become ill.

Fact 2: Bacteria, viruses or parasites can cause sickness.

Given the two facts above, answer the question "what causes illness?" with the following options: 
- health
 - parasites
 - chickenpox
 - toxins
 - viruses
 - exercise
 - wellness
 - Roundworms.


 

  parasites       