The correct option is D Spermiogenesis - formation of spermatozoa; spermiation - release of spermatozoa from Sertoli cells into the cavity of seminiferous tubules.
Spermatogenesis is the process of formation of haploid sperms from diploid male germ cells, spermatogonia. It involves mitotic cell division, meiosis and the process of spermiogenesis.
Spermatogonia multiply by mitosis and increase in number. Some of them differentiate into primary spermatocytes and undergo meiosis I to form haploid secondary spermatocytes. The secondary spermatocytes undergo meiosis II to form haploid spermatids.
Spermiogenesis is the process by which haploid round spermatids undergo a series of events to become spermatozoa (sperms) which are capable of motility.
After spermiogenesis, the sperm heads get embedded in the Sertoli cells and draw nourishment.
Sperms are finally released from the Sertoli cells into the lumen of seminiferous tubules. This process of release of sperms is called spermiation.