The correct option is C Annelid
The 'sea mouse', Aphrodita aculeata, is a marine polychaete worm which is found in the North Atlantic, the North Sea, the Baltic Sea and the Mediterranean. It has been found at depths of over 3,000 meters. The sea mouse is an active predator and scavenger feeding primarily on small crabs, hermit crabs and other polychaete worms. It belongs to phylum Annelida. Hence, option A is correct.