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
Alpha blocker useful in BPH is: 
Select and explain. 
A. Phentolamine, B. Prazosin, C. Tolazoline, D. Phenoxybenzamine
B: Prazosin
Answer: B: Prazosin 
Explanation: None