Concept:Earthworms possess specialised tubular excretory organs called nephridia.Explanation:Nephridia are segmentally arranged tubes that remove nitrogenous waste from the body fluid.They filter waste and expel it through external pores.Other options are found in different organisms: Malpighian tubules in insects, flame cells in flatworms, and kidneys in vertebrates.Therefore, the earthworm uses nephridia for excretion.Answer:C. nephridium