Fact 1: Viruses are not cells.

Fact 2: Influenza viruses mutate.

Given the two facts above, answer the question "What is not a cell?" with the following options: 
- all matter
 - layers of fat
 - illness
 - bacteria
 - influenza
 - Leptospirosis
 - an object
 - hydrocarbons


 

     influenza    