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': 'Least toxic compound of lead is : \nSelect and explain. \nA. Least toxic compound of lead is :, B. Lead oxide, C. Lead carbonate, D. Lead sulphide', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Lead sulphide', 'role': 'assistant'}]