All of the following are coelomates except:

Explanation

These are the animals having a true body cavity or coelom. The cavity is filled with coelomic fluid. Coelomates are classified as protosomes and deuterostomes. OPTION A: Deuterostomes develop the anus first, then the mouth at the other end of the embryo. Deuterostomes are coelomate animals. OPTION B: All the animals from phylum Annelida to the phylum Chordata are coelomates. OPTION C: Protostomes develop so that the first opening in the embryo is the mouth. Protostomes are bilaterally symmetrical and have three germ layers, the organ level of organization, the tube within-a-tube body plan, and a true coelom. OPTION D: Aschelminthes are called pseudocoelomates. Hence, D is the correct option.