You are presented with the question "organisms belonging to the phylum Platyhelminthes have evolved a close association with their what" and the following answer choices: 
- ovaries
 - Wasps
 - life
 - plant
 - orchids
 - hosts
 - root system
 - tree host

Now knowing that flatworms belong to the phylum Platyhelminthes and parasitic flatworms have evolved a close association with their hosts, choose the best answer.


 

      hosts   