Which describes a difference between bivalves and cephalopods?

a) bivalves use tube feet for movement, and cephalopods use muscular feet for movement.
b) bivalves live only in ocean environments, and cephalopods live in a variety of aquatic environments.
c) bivalves use a radula to feed, and cephalopods use filter-like structures to feed.
d) bivalves have an open circulatory system, and cephalopods have a closed circulatory system.