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': 'One TB unit is recommended for how much population in Hilly areas ? \nSelect and explain. \nA. 50,000, B. 100,000, C. 150,000, D. 250,000', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., 250,000", 'role': 'assistant'}]