Correct Answer: (a) Cnidaria
Solution:Sea anemones are ocean-dwelling members of the phylum Cnidaria. They are invertebrates belonging to the class of Anthozoa. The name Cnidaria (with a silent ‘c’) refers to the cnidae, or nematocysts, that is, the cellular entity of the venom apparatus, which all Cnidarians possess. The phylum Cnidaria includes anemones, corals, jellyfish (including box jellyfish), and hydras.