Concept:Parasites that live inside the host's body are called internal parasites, or endoparasites.Explanation:Mite, louse, and tick all live on the surface or skin of the host, so they are external parasites.Ascaris, however, is a roundworm that survives within the intestines of its host.Therefore, ascaris is the parasite that lives inside the body of its host.Answer:C. ascaris