The __________ is the Simplest,but Least Common Body Form of Sponge

Question

The __________ is the simplest,but least common body form of sponge.
A)leucon
B)sycon
C)demosponge
D)ascon
E)sclerosponge

Accepted Answer

The ascon is the simplest body form of sponge, consisting of a tube-like structure with a single osculum (exhalant opening) and one or more inhalant pores called ostia. However, it is the least common body form among sponges.