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': 'True about esmolol is: \nSelect and explain. \nA. It has no intrinsic sympathomimetic activity, B. It is a cardioselective β–blocker, C. It can precipitate heart failure, D. All of these', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]