Flatworms Differ from Nematodes in That Flatworms

Flatworms differ from nematodes in that flatworms

A) are radially symmetrical, whereas nematodes are bilaterally symmetrical.
B) lack a cuticle, whereas nematodes secrete a cuticle that they molt.
C) have two embryonic cell layers, whereas nematodes have three.
D) have two openings to the digestive cavity, whereas some nematodes lack a digestive tract.
E) lack an anterior brain, whereas nematodes have a small anterior brain.