1) Ringworm causes contagious fungal infection on the outer layer of skin. 2) Pinworm infection is an infection of the large intestine and anal area by a small, white parasite, pinworm. Pinworms are also called Threadworm due to their thread-like appearance. 4) Tapeworms are flatworms that can live in the intestines and cause infection. So the correct answer is A ‘Ringworm’.