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': 'Population covered by a PHC in hilly region is – \nSelect and explain. \nA. 20000, B. 30000, C. 40000, D. 25000', 'role': 'user'}, {'content': 'Answer: A \nExplanation: One PHC for every 30,000 rural population in the plains.\nOne PHC for every 20,000 population in hilly, tribal and backward areas.', 'role': 'assistant'}]