This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
[{'content': 'Peripheral iridectomy is must in which of the following? \nSelect and explain. \nA. Primary open-angle glaucoma, B. Absolute glaucoma, C. Closed-angle glaucoma, D. Cataract', 'role': 'user'}, {'content': 'Answer: C \nExplanation: .', 'role': 'assistant'}]