(d) : Mollusca includes those animals which have soft bodies, usually furnished with a shell. The body is often divided into a head, with eyes or tentacles, a muscular foot and a visceral mass housing the organs. Loligo (squid or sea arrow), Teredo (shipworm), Octopus are some of their examples.
In option (a) Spongilla and Euplectella belong to porifera but Pennatula (the sea pen or sea feather) belongs to coelenterata. In option (b) Physalia and Aurelia belong to cnidaria but Bonellia belongs to Phylum Annelida. In option (c) Planaria and Schistosoma belong to platyhelminthes but Enterobius (Pinworm) belongs to aschelminthes.