This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'Sunflower cataract is caused by \nSelect and explain. \nA. Siderosis, B. Chalcosis, C. Lead intoxication, D. Silicosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Chalcosis is copper alloy in the eye Refer: Khurana 6th edition page number 194', 'role': 'assistant'}]