This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'Common salt can be used as a chemical antidote for washing the stomach in case of oral poisoning by \nSelect and explain. \nA. Mercuric sulphide, B. Silver nitrate, C. Copper sulphate, D. Lead bicarbonate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]