Identify an example of diploblastic animals.

Correct option is D

Coelenterates are an example of diploblastic animals.
 Diploblastic animals are those that develop from two germ layers, the ectoderm and the endoderm.
 They do not have a third germ layer, the mesoderm, which is present in triploblastic animals.
 Coelenterates, also known as Cnidarians, are a group of diploblastic animals that include jellyfish, coral, and sea anemones.
 Platyhelminthes (flatworms) are an example of triploblastic animals.
 Arachnids are also triploblastic animals and belong to the phylum Arthropoda, which includes insects, spiders, and crustaceans.
 Chordates, which include fish, birds, mammals, and humans, are also triploblastic animals.