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': 'Earliest clinical manifestation of siderosis bulbi \nSelect and explain. \nA. Iris is stained greenish, B. Retinal pigmentary degeneration, C. Glaucoma, D. Rusty deposits in the anterior subcapsular cells of the lens', 'role': 'user'}, {'content': 'Answer: D \nExplanation: These rusty deposits are arrested radially in a ring ---- Earliest manifestation.', 'role': 'assistant'}]