Answer: Seminiferous tubules.
- A Seminiferous tubules
- B Vasa efferentia
- C Rete testis
- D Ejaculatory ducts
Correct answer: A. Seminiferous tubules
Explanation: Sperm are produced inside the seminiferous tubules of the testis, which are lined by germinal epithelium.

The human male reproductive system: sperm formed in the testis mature in the epididymis and travel via the vas deferens, mixing with secretions of the seminal vesicle, prostate and bulbourethral glands. Image: Wumingbai, CC BY-SA 4.0, via Wikimedia Commons.
Concept context
Male and female reproductive systems, gametogenesis, fertilization, implantation, pregnancy, and reproductive health.