You are presented with the question "What are usually considered to be nonliving?" and the following answer choices: 
- direct damage to the lungs
 - bacteria
 - harmful substances
 - major threat to health
 - humans
 - the smallest agents of disease
 - starfish
 - Contaminated wounds

Now knowing that viruses are usually considered to be nonliving and viruses Viruses are the smallest agents of disease, choose the best answer.


 

      the smallest agents of disease   