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 caused by \nSelect and explain. \nA. Iron, B. Lead, C. Copper, D. Mercury', 'role': 'user'}, {'content': 'Answer: C \nExplanation: “Chalcosis refers to specific changes made by copper containing alloys in eye” Features of chalcosis are:\n√ KF rings on descement membrane of cornea\n√ Sunflower cataract\n√ Golden brown metallic sheen plaques on the retinal pole', 'role': 'assistant'}]