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': "Argon laser is used in all except: \nSelect and explain. \nA. Retinal detachment, B. Retinitis pigmentosa, C. Retinal vein occlusion, D. Eales' disease", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Retinitis pigmentosa', 'role': 'assistant'}]