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': 'Male to Female ratio is - \nSelect and explain. \nA. Males for 1000 population, B. Females for 1000 males, C. Males for 1000 females, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Females for 1000 males", 'role': 'assistant'}]