This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
In the management of symptomatic Benign Prostatic Hyperplasia with finasteride the period of trial required for determining a satisfactory response is 
Select and explain. 
A. 1 month, B. 2 months, C. 4 months, D. 6 months
D: 6 months
Answer: D: 6 months 
Explanation: Finasteride is 5-alpha reductase inhibitor which inhibits conversion of testosterone to dihydrotestosterone. It is effective in palpably enlarged prostate(>50g). 5mg is used daily for at least 6 months for satisfactory response. It has fewer side effects. It is contraindicated in obstructive uropathy or carcinoma prostate.Reference : page 1047 SRB&;s manual of surgery 5th edition and page 1350 Bailey and Love&;s sho practice of surgery 25th edition