You are presented with the question "What can roundworms do?" and the following answer choices: 
- killing insects
 - Make money
 - survive
 - Start fires
 - Harm hosts
 - Harm themselves
 - protect them
 - reproduce

Now knowing that roundworms may be free-living or parasitic and internal parasites harm their hosts in many ways, choose the best answer.


 

     Harm hosts    