Concept:Gut parasites live inside the digestive tract, whereas ticks, fleas, and lice are external parasites.Explanation:Ticks, fleas, and lice attach to the skin or hair of livestock, so they are ectoparasites.Roundworms live inside the intestine, which is part of the gut.Hence, among the given options, the roundworm is the parasite found in the gut.Answer:C. Roundworm