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': "Elschnig's pearls are a sign of: \nSelect and explain. \nA. Chronic uveitis, B. Secondary cataract, C. Cystoid macular oedema, D. All of the above", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Secondary cataract', 'role': 'assistant'}]