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': 'Best indicator of availability,utilisation & effectiveness of health services- \nSelect and explain. \nA. IMR, B. MMR, C. Hospital bed OCR, D. DALY', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., IMR", 'role': 'assistant'}]