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': 'Minimum duration of developing coal minor pneumoconiasis is – \nSelect and explain. \nA. 2–4 years, B. 4–6 years, C. 8–10 years, D. More than 10 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Coal worker pneumoconiosis (Antracosis) \n\nThere are two general phases in coal miners pneumoconiosis\n\n\nThe first phase :\xa0Simple pneumoconiosis : This is associates with only little ventilatory impairment but requires 12 years of work exposure for its development.\nThe second phase : Progressive massive fibrosis : This is associated with severe respiratory disability and takes much longer.', 'role': 'assistant'}]