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 of 1000 is covered by – a) Anganwadi workerb) Health assistantc)  Trained Daid)  Village health guide \nSelect and explain. \nA. abc, B. ad, C. bc, D. acd', 'role': 'user'}, {'content': "Answer: D \nExplanation: Population of 1000 is covered by :\n\n\nAnganwadi worker\nTrained Dai\nVillage health guide\n\nAbout option 'b'\nA Health assistant → Per 30000 population in plains, and per 20000 population in hilly, tribal and backward areas.", 'role': 'assistant'}]