The correct option is D Spermiation
Spermiogenesis
Spermiogenesis is the process of transformation of spermatids into spermatozoa.
Spermiation
After spermatogenesis, sperm heads become embedded in the Sertoli cells to obtain nourishment from them and finally they are released from the Sertoli cells into the seminiferous tubules. This process is called spermiation.
Spermatogenesis
Spermatogenesis is the process of formation of spermatozoa from spermatogonia starting at puberty.
Fertilisation
Fertilization is the event of fusion of sperm and ovum.
Gametogenesis
The process of formation of gametes in gonads (testes and ovaries) is called gametogenesis.