All animals are descended from a (n) A. multicellular prokaryote ancestor. B. ancestral bilateral prokaryote. C. ancestral protist. D. ancestral symmetric animal. E. multicellular radial animal.

A. multicellular prokaryote ancestor.

Explanation:

Multicellular organisms are organisms that consist of many cells. Animals (Humans), plants and fungi are multicellular organisms, therefore life processes such as feeding, digestion, reproduction, respiration and excretion occurs in different cells.

A Prokaryote is a single cell organism that has no nucleus membrane nor other membrane organelles. It is belived that the first living organisms are said to br prokaryote, they are asexual in nature.

From prokaryotes, which are known to be the first living organisms to muticellular organisms, we can deduce that humans (animals) are descended from muticellular prokaryote ancestor.