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 primary angle-closure glaucoma pilocarpine lowers the intraocular pressure by its direct action on the: \nSelect and explain. \nA. Sphincter pupillae muscle, B. Ciliary epithelium, C. Trabecular meshwork, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Sphincter pupillae muscle', 'role': 'assistant'}]