Which of the following statements is correct?
a. most animal phyla belong to the clade radiata.
b. eumetazoans have three embryonic tissue layers.
c. the origin of all extant animal phyla can be traced to the cambrian explosion.
d. all animals share a common ancestor.
e. sponges are diploblastic animals.

D. All animals share a common ancestor.

Explanation:

Alternative A is FALSE because most animal phyla belong to the bilateria clade;Alternative B is FALSE because cnidaria are diploblastic (two embryonic tissue layers) and belong to eumetazoa.Alternative C is FALSE because animal phyla originated from the Ediacaran biota in the Precambrian period. Alternative D is TRUE. All animals evolved from a common ancestor. Alternative E is FALSE because Sponges are triploblastic animals.

If it doesn't have a nucleus its a prokaryote