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: Ophthalmology
[{'content': 'Chalcosis is seen with \nSelect and explain. \nA. Pb, B. Cu, C. Fe, D. Hg', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Cu', 'role': 'assistant'}]