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 shoest acting betablocker: September 2006 \nSelect and explain. \nA. Acebutolol, B. Sotalol, C. Bisoprolol, D. Esmolol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D: Esmolol', 'role': 'assistant'}]