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': 'Safe disposal of mercury is – \nSelect and explain. \nA. Collect carefully and recycle, B. Controlled combustion, C. Treatment with chemicals, D. Deep burial', 'role': 'user'}, {'content': 'Answer: A \nExplanation: All mercury and mercury-containing items should be recycled.\nIt should never be poured down a drain or sewer, flushed down a toilet, or thrown in the thrash.\nAs long as mercury is recycled, it will stay in the recycling loop, going into new products rather than into the environment.', 'role': 'assistant'}]