Spermiation is the process of releasing mature sperms from:

The correct answer is Option (3) → Seminiferous tubules

Option (3) Seminiferous tubules — Correct. After spermiogenesis the sperm heads stay embedded in the Sertoli cells. They are finally released from the seminiferous tubules; this release is called spermiation.

NCERT Extract:
Gametogenesis – “… The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids (Figure 2.5). … 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.”