Bilateral symmetry is found in (a) Cnidaria(b) Platyhelminthes(c) Mollusca(d) Both (b) & (c)

Bilateral symmetry refers to the body plan in which an organism can be divided into mirror-image halves along only one plane. Let's analyze each of the given options:

(a) Cnidaria: These organisms (e.g., jellyfish, sea anemones) have radial symmetry, meaning their body is organized around a central axis. Bilateral symmetry is not found in this group.

(b) Platyhelminthes: This phylum includes flatworms, which exhibit bilateral symmetry. These organisms have a distinct left and right side.

(c) Mollusca: Most members of this phylum (e.g., snails, clams, squids) show bilateral symmetry during at least one stage of their life cycle. Therefore, Mollusca are also bilaterally symmetrical.

(d) Both (b) & (c): Since both Platyhelminthes and Mollusca exhibit bilateral symmetry, this option is correct.

Correct Answer: (d) Both (b) & (c)