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: Pathology
[{'content': "Pink's disease is due to \nSelect and explain. \nA. Toxicity of silver, B. Toxicity of Mercury, C. Toxicity of Lead, D. Toxicity of Tetracycline", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]