Fact 1: Immunodeficiency occurs when the immune system is not working properly.

Fact 2: Many cancers can cause immunodeficiency.

Given the two facts above, answer the question "Many _ can cause the immune system to not work properly." with the following options: 
- fever
 - bacteria
 - radiation
 - fungi
 - A drug.
 - Allergies
 - cancers
 - Toxicity


 

       cancers  