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': 'In which system, continuous enumeration of bihs and deaths by enumerator and an independent survey by investigator supervisor is done ? \nSelect and explain. \nA. Decadal Census Enumeration, B. Sample Registration System, C. Model Registration System, D. National Family Health Survey', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Sample Registration System", 'role': 'assistant'}]