Which Is a Step Included in the Process of Spermatogenesis

Which is a step included in the process of spermatogenesis?

A) The spermatogonia near the basement membrane of the seminiferous tubules degrade.
B) The spermatogonia pass the blood-testis barrier to differentiate into primary spermatocytes.
C) The spermatogonia undergo meiosis to produce haploid primary spermatocytes.
D) The secondary spermatocytes in the seminiferous tubules undergo DNA replication.
E) The primary diploid spermatocytes undergo mitosis to produce secondary haploid spermatocytes.