Which Step in Steroid Hormone Biosynthesis Occurs in the Accessory $5 \alpha$

Which step in steroid hormone biosynthesis occurs in the accessory sex target tissues of the male and is catalyzed by $5 \alpha$ -reductase?

A) Cholesterol $\rightarrow$ pregnenolone
B) Progesterone $\rightarrow$ 11-deoxycorticosterone
C) 17-Hydroxypregnenolone $\rightarrow$ dehydroepiandrosterone
D) Testosterone $\rightarrow$ estradiol
E) Testosterone $\rightarrow$ dihydrotestosterone