This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Alpha 1a selective blocker is \nSelect and explain. \nA. Tamsulosin, B. Prazosin, C. Yohimbine, D. Idazoxan', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tamsulosin, silodosin are more selective alpha blockers in prostrate uhera.used for BPH. Ref: KD Tripathi 8th ed.', 'role': 'assistant'}]