In a specimen-based viva, the examiner describes this case: a leaf-shaped parasite lives in the bile ducts of sheep and is commonly called liver fluke. Choose the concept that fits it best.

Fasciola hepatica is the liver fluke, a trematode parasite of sheep and other mammals. It has economic importance because it can damage livestock health and productivity. This MCQ belongs to the Trematoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.