Final answer:
A kitten with a pot-bellied appearance and a dull coat is most likely suffering from an infestation of roundworms, a type of nematode. Option C is correct.
Step-by-step explanation:
If you see a kitten with a pot-bellied appearance and a dull coat, the parasite you would suspect is C) Roundworms. Roundworms are a type of nematode that can cause these symptoms in kittens. They live in the intestinal tract and can lead to a distended abdomen, giving the kitten a pot-bellied look, as well as a dull coat due to the nutritional deficiencies and general ill health they can cause.
In contrast, fleas and ticks are external parasites, which might cause itchiness and hair loss, but not a pot-bellied appearance, and tapeworms, though they are internal parasites like roundworms, typically do not cause such a pronounced pot-belly in their hosts.