The correct answer is B, Heterophyes heterophyes.  The metacercaria of Heterophyes encyst in the flesh of fish and are infectious when ingested.  The other listed parasites do not have fish as a vehicle of transmission.  Freshwater plants are the source of transmission for Fasciola hepatica and Fasciolopsis buski.  Schistosoma mansoni produce infective cercariae that penetrate the skin to initiate human infection.