This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ANS, Subject name: Pharmacology
[{'content': "An old patient Ram Kishore having asthma and glaucoma is to receive a b blocker. Regarding b blocking drugs: \nSelect and explain. \nA. Metoprolol blocks b2 receptors selectively, B. Esmolol's pharmacokinetics are compatible with chronic topical use, C. Nadolol lacks b2 blocking action, D. Timolol lacks the local anaesthetic effects of propanolol", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Metoprolol is a cardioselective (b1 selective) blocker and not b2 selective. Esmolol is the shoest acting b -blocker and is useful for acute treatment. Nadolol is a non-selective b-blocker. It blocks both b1 as well as b2 receptors. Propanolol possesses maximum local anaesthetic activity whereas timolol lacks this propey.', 'role': 'assistant'}]