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 trabeculoplasty is used in: \nSelect and explain. \nA. Closed-angle glaucoma, B. Primary open-angle glaucoma, C. Neovascular glaucoma, D. Aphakic glaucoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Primary open-angle glaucoma', 'role': 'assistant'}]