A student encounters an animal embryo at the eight-cell stage. The four smaller cells that comprise one hemisphere of the embryo seem to be rotated 45 degrees and to lie in the grooves between larger, underlying cells (i. e., spiral cleavage). This embryo may potentially develop into a(n):.
A) turtle.
B) earthworm.
C) sea star.
D) fish.
E) sea urchin.