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': 'The breeding ground for the vectors of Japanese \nSelect and explain. \nA. Paddy field, B. Mixed garbage, C. Cooler water, D. Stale food', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]