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': 'Respirable dust for pneumoconiosis \nSelect and explain. \nA. 0.1–5 m, B. 5–10 m, C. 10–15 m, D. 15–20 m', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]