The correct option is
B Crustacean
Crayfish, also known as crawfish, crawdads, freshwater lobsters, mountain lobsters, mudbugs, or yabbies are freshwater crustaceans resembling small lobsters (to which they are related).
Crustaceans form a large, diverse arthropod taxon which includes such familiar animals as crabs, lobsters, crayfish, shrimps, prawns, krill, woodlice, and barnacles. Like other arthropods, crustaceans have an exoskeleton, which they moult to grow.
So, the correct answer is 'A'.