Fact 1: Viruses are not cells.

Fact 2: Viruses Viruses are the smallest agents of disease.

Given the two facts above, answer the question "Cells do not include" with the following options: 
- harmful substances
 - sulfate particles
 - the smallest agent of disease
 - direct damage to the lungs
 - sub-units of species
 - Inches or fractions of inches.
 - Something with a head, thorax, and abdomen
 - Direct sunlight.


 

   the smallest agent of disease      