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
Which of the following alpha-blocker drug is used in BPH without producing hypotension? 
Select and explain. 
A. Doxazosin, B. Phentolamine, C. Tamsulosin, D. Terazosin
C: Tamsulosin
Answer: C: Tamsulosin 
Explanation: Ans. C. Tamsulosina. Tamsulosin, Silodosinb. Higher affinity for a1A/1D receptors (found on prostate smooth muscle) than for a1B subtype (found on vascular smooth muscle)c. Minimal effect on blood pressured. High oral bioavailabilitye. Silodosin is a newer a1A blocker used in BPH.