Which one of the following groups of animals is bilaterally symmetrical and triploblastic?

Options

(a) Aschelminthes (round worms)
(b) Ctenophores
(c) Sponges
(d) Coelenterates (Cnidarians)

Correct Answer:

Aschelminthes (round worms)

Explanation:

Aschelminthes is bilaterally symmetrical and triploblastic. These are mostly aquatic, free living or parasitic. Their body is three layered which is ectoderm, mesoderm and endoderm.