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': 'In angle closure glaucoma, obstruction to outflow of aqueous humour mainly due to the involvement of: September 2007 \nSelect and explain. \nA. Canal of schlemm, B. Trabecular meshwork, C. Iris, D. Scleral venous plexus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Iris', 'role': 'assistant'}]