What is spermiation?

The correct answer is Option (2) → Release of sperms from the seminiferous tubules.

Sperm formation ends in two steps with similar names. In spermiogenesis the spermatids are transformed into sperms. The sperm heads then stay embedded in the Sertoli cells, and are finally released from the seminiferous tubules. This release is called spermiation.

Option (1) Formation of Sertoli cells. — Incorrect. Sertoli cells line the seminiferous tubules and provide nutrition to the germ cells. Spermiation has nothing to do with their formation.

Option (2) Release of sperms from the seminiferous tubules. — Correct. Spermiation is the release of the sperms from the seminiferous tubules, after their heads have been held in the Sertoli cells.

Option (3) Formation of spermatids. — Incorrect. Spermatids are formed when the secondary spermatocytes undergo the second meiotic division. This is a step of spermatogenesis, not spermiation.

Option (4) Transformation of spermatids into spermatozoa. — Incorrect. The transformation of spermatids into spermatozoa is spermiogenesis. Spermiation comes after it.

NCERT Extract:
Gametogenesis – “… The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis. After spermiogenesis, sperm heads become embedded in the Sertoli cells, and are finally released from the seminiferous tubules by the process called spermiation.”