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': 'Beta blocker with a-blocker capacity is ? \nSelect and explain. \nA. Atenolol, B. Labetelol, C. Propanolol, D. Metoprolol', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Labetelol Combined alpha & beta blockers o Carvedilol o Bucindolol o Nipradilol o Medroxalol o Labetalol o Bevantolol o Dilevalol", 'role': 'assistant'}]