Answer: B. Bilateral
Explanation: Annelids, which include earthworms and leeches, exhibit bilateral symmetry. This means that their bodies can be divided into two equal halves along one plane, typically the longitudinal axis. This type of symmetry is common in many organisms, allowing for a complex and organized body structure that can lead to efficient movement and the development of specialized body parts. In contrast, radial symmetry, seen in organisms like jellyfish, involves multiple planes of symmetry around a central axis. Annelids do not have this structure, making bilateral symmetry the correct answer.