How can you distinguish an ectoproct from a hydroid?

A)The hydroid colony is very small,perhaps a few millimeters long,while the ectoproct is centimeters long
B)The hydroid has the anus within the tentacular crown and the ectoproct has the anus outside the crown
C)The hydroid lacks any complex digestive gut including any anus
D)The hydroid has more complex musculature and innervation
E)Only hydroids form moss-like colonies