Flatworms belong to the phylum Platyhelminthes, and flatworms are bilaterally symmetric. Given these facts, what does the phylum Platyhelminthes usually have among the following options:
- resistance
 - Veins and arteries.
 - Leptospirosis
 - sensory neurons
 - bilateral symmetry
 - parasites
 - food and shelter
 - aerobic capacity


 

     bilateral symmetry    