Fact 1: Some viruses can cause cancer.

Fact 2: Cancer is an uncontrolled growth and spread of abnormal cells.

Given the two facts above, answer the question "What can cause an uncontrolled growth and spread of abnormal cells?" with the following options: 
- smoking cigarettes
 - some foods
 - Pesticides
 - cigarettes
 - smoking
 - some religions
 - some viruses
 - some books


 

       some viruses  