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': 'Which of the following drugs act on trabecular meshwork and affects the aqueous outflow? \nSelect and explain. \nA. Timolol, B. Pilocarpine, C. Brimonidine, D. Brinzolamide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]