This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: parasitology, Subject name: Microbiology
[{'content': 'The definitive host for echinococcous granulosus is - \nSelect and explain. \nA. Man, B. Sheep, C. Fox, D. Dog', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Dog ,wolf ,jackal,fox etc can act as definitive host...but the optimal one is dog Sheep and cattle can act as intermediate host. Ref: panikers textbook of Medical parasitology 8th edition page 130', 'role': 'assistant'}]