In spermatogenesis, reduction division of chromosome occurs during conversion of 

The germ cells of seminiferous tubules present near the capsule serve as spermatogonia, which divide and produce more cells by mitosis. Some of these new cells serve as primary spermatocytes that undergo meiosis, meiosis I produce two secondary spermatocytes (n), which is followed by meiosis II that produces four spermatids. Spermatids then differentiate into sperm where only morphological changes take place and no cell division occurs during differentiation of spermatids into sperms. Thus, the correct answer is option B.