The immature male germ cell undergo division to produce sperms by the process of spermatogenesis. Choose the correct one with reference to above.

a. Spermatogonia have 46 chromosomes and always undergo meiotic cell division

b. Primary spermatocytes divide by mitotic cell division

c. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division

d. Spermatozoa are transformed into spermatids