Identify animals that are NOT triploblastic.

Correct option is C

Coelenterates are not triploblastic. Triploblastic animals are those that develop from three germ layers: the ectoderm, mesoderm, and endoderm. Coelenterates (Cnidarians) like jellyfish, sea anemones, and corals are diploblastic, meaning they develop from only two germ layers: the ectoderm and endoderm.