Sea Pens Are Distinctly Different from Sea Anemones in That

Sea pens are distinctly different from sea anemones in that

A) sea pens contribute to formation of islands and reefs, while anemones destroy them.
B) sea pens break down decaying organic matter, while anemones are carnivorous.
C) sea pens are composed of two or more different kinds of polyps, while anemones only have one type.
D) sea pens are solitary, while anemones are colonial.
E) the medusa stage of sea pens is mobile, while anemones have a sessile medusa.