This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Example for "AMPLIFIER HOST" - \nSelect and explain. \nA. Pig in JE, B. Dog in hydatid disease, C. Cattle in mad cow disease, D. Rat in plague', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]