Placozoans Are Structurally Simple

Placozoans are structurally simple.They have no mouth, gut, or nervous system and only a few distinct cell types.This simplicity it thought to be secondarily derived, because they

A) are composed of an upper and lower body surface that sandwiches a layer of contractile fibers.
B) are sessile filter feeders.
C) exhibit asexual and sexual reproduction.
D) have an asymmetrical adult stage.
E) are found in tropical and subtropical oceans.