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
Alpha 1a selective blocker is 
Select and explain. 
A. Tamsulosin, B. Prazosin, C. Yohimbine, D. Idazoxan
A: Tamsulosin
Answer: A: Tamsulosin 
Explanation: Tamsulosin, silodosin are more selective alpha blockers in prostrate uhera.used for BPH. Ref: KD Tripathi 8th ed.