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': 'Crude birth rate denominator is - \nSelect and explain. \nA. Total no of live births in that year, B. 1000 live births, C. Total numbers of births, D. Mid year population', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]