Finasteride's action in the treatment of benign prostatic hypertrophy is a (an).. Serotonin reuptake inhibitor

Finasteride's action in the treatment of benign prostatic hypertrophy is a (an):
A. HMG- CoA reductase inhibitor
B. Alpha-5reductase inhibitor
C. Serotonin reuptake inhibitor
D. P450 hepatic enzyme inhibitor
E. None of the above.