This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
[{'content': 'Which of the following is beta (b2) antagonistic: \nSelect and explain. \nA. Esmolol, B. Betaxolol, C. Butoxamine, D. Celiprolol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (Butoxamine): Ref: 125-KDT (136-KDT 6th)CLASSIFICATION OF b ADRENERGIC BLOCKING AGENTSNonselectgive (b1 and b2)Cardio selective (b1)Selective (b2)a. without intrinsic sympatho mimetic activity- Propranolol, sotalol, timololMetoprololButoxamine ICI 118551Atenolol Acebutolol b. With intrinsic sympathomimetic activity- PindololBisoprolol Esmolol Betaxolol c. With additional a blocking property Labetalol, carvediololCarvedilol', 'role': 'assistant'}]