Fact 1: Viruses cause many human diseases.

Fact 2: Human viruses are created by natural process.

Given the two facts above, answer the question "Something that can cause many human diseases can be what?" with the following options: 
- deadly and devastating
 - Disease textbooks
 - harmful substances
 - Microscopic organisms
 - Human thoughts
 - destroying life
 - Human emotions
 - Created by a natural process.


 

        Created by a natural process. 