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: Pharmacology
[{'content': 'Which of the following is the longest acting ocular beta blocker ? \nSelect and explain. \nA. Timolol, B. Betaxolol, C. Carteolol, D. Metoprolol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Beta blockers used in Glaucoma- Timolol, levobunolol, Carteolol, betaxolol\nMetoprolol, though a beta blocker is not used for glaucoma because of its local anaesthetic property. Drugs having local anaesthetic property will increase the risk of corneal ulcers.\nBetaxolol is longer acting than Timolol or others.', 'role': 'assistant'}]