This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following is the longest acting ocular Beta blocker \nSelect and explain. \nA. Timolol, B. Betaxolol, C. Caiolol, D. Metoprolol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref-KDT 6/e p145 Betaxolol is a cardioselective Beta blocker useful in glaucoma.it is longer acting than timolol .another non selective Beta blocker used topically for the treatment of glaucoma is levobunolol.', 'role': 'assistant'}]