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 a cardioselective β - blocker \nSelect and explain. \nA. Timolol, B. Metaprolol, C. Carvedilol, D. Propanolol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Metaprolol is a selective\xa0β1 receptor blocker, hence cardioselective.\nNote: Carvedilol\xa0is prefered in CHF cases even though its non selective\xa0β - blocker. Because it has additional anti-oxidant & anti-inflammatory property.', 'role': 'assistant'}]