You are presented with the question "What doesn't protect plants?" and the following answer choices: 
- viruses
 - smallpox
 - herbicide
 - steroids
 - A virus
 - Nematoda
 - chickenpox
 - cigarettes

Now knowing that apesticide is used for protecting plants by killing insects and plants are poisoned by herbicides, animals by pesticides, choose the best answer.


 

   herbicide      