Which term includes snails, clams, and octopuses?

Which term includes snails, clams, and octopuses?

• A. Gastropod
• B. Mollusk
• C. Cephalopods
• D. Bivalve

Answer: (B)

In biology, many animals are grouped into a phylum that contains all related classes. Snails, clams, and octopuses all belong to the same phylum, Mollusca. Snails are gastropods, clams are bivalves, and octopuses are cephalopods, so each is a different class within that phylum. The term that includes all of them is mollusk, the broad category for the entire group. The other terms point to smaller groups: a gastropod covers only snails and their relatives; a cephalopod covers octopuses and their relatives; a bivalve covers clams and their close relatives. So the best answer is mollusk.