Correct Option: C

A clitellum is part of a of the reproductive system of clitellates, a subgroup of annelids which contains oligochaetes (earthworms) and hirudineans (leeches). The clitellum is a thick, saddle-like, ring found in the epidermis (skin) of the worm, usually with a light colored pigment. To form a cocoon for its eggs, the clitellum secretes a viscous fluid.