Which Class of Flatworms is Free-Living (Not Parasitic)

Question

Which class of flatworms is free-living (not parasitic)?
A) Cestoidea (tapeworms)
B) Trematoda (flukes)
C) Turbellaria (planaria)
D) Hirudinea (leeches
E) Oligochaeta (earthworm)

Accepted Answer

Turbellaria, which includes planarians, is the class of flatworms that are primarily free-living and not parasitic, unlike the other classes listed which include organisms that are mostly parasitic or belong to different phyla.