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: Forensic Medicine
[{'content': 'Plumbism is caused by. \nSelect and explain. \nA. Lead poisoning, B. Mercury poisoning, C. Thallium poisoning, D. Copper poisoning', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Lead', 'role': 'assistant'}]