This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Osteoporosis, Sex Hormones and OCPs, Subject name: Pharmacology
A drug 'X' primarily reduces the static component of urinary obstruction in benign hyperophy of prostate and takes more than 3 months to exe its beneficial effect. Which of the following is 'X'? 
Select and explain. 
A. Tamsulosin, B. Terazosin, C. Finasteride, D. Amphetamine
C: Finasteride
Answer: C: Finasteride 
Explanation: 5-a-reductase inhibitors: Finasteride reduce the static component of urinary obstruction in BHP--> Delayed action >3months Selective a1 blockers are used to relieve the dynamic obstruction in BHP-->provides rapid symptomatic relief.