How Do the Tube Feet of Sea Stars and Sea

Multiple Choice

How do the tube feet of sea stars and sea urchins operate?

A) Sticky threads lead back to the mouth and primitive brain
B) Cilia transport hemolymph from chamber to chamber
C) Actin and myosin in muscles in the five arms or "rays" constrict the tube feet directly when stimulated by nerves from the sea star brain
D) A hydraulic system regulates water pressure in the tube feet
E) Each tube foot is an independent organism and the sea star is a colonial mass