This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sympathetic System, Subject name: Pharmacology
[{'content': 'The propey which makes betaxolol different from timolol is that betaxolol : \nSelect and explain. \nA. is a b1 selective blocker, B. is more efficacious in glaucoma, C. produces less ocular side effects, D. is shoer acting', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Betaxolol is cardioselective Beta blocker (i.e Beta-1 blocker) Timolol is non-selective Beta blocker(Beta 1 + Beta 2) Betaxolol - less bronchopulmonary and less cardiac, central and metabolic side effects. Betaxolol has protective effect on retinal neurons independent of i.o.t. lowering, by blocking some Ca2+channels and reducing Na+/Ca2+ influx. This action is more prominent in betaxolol than in timolol. Betaxolol is less efficacious in lowering i.o.t. than timolol, because ocular Beta receptors are predominantly of the Beta 2 subtype.', 'role': 'assistant'}]