Animals with a Coelom Have an Advantage Over Other Triploblastic

Animals with a coelom have an advantage over other triploblastic animals because they

A) have better control over movement than other triploblasts.
B) have more appendages than other triploblasts.
C) show less cephalization than other triploblasts.
D) lack mesenchyme, providing more space for internal organs.
E) possess a nerve net, which enhances their ability to feed.