What structure is primarily responsible for the production of sperm in males?

The testis is the primary structure responsible for the production of sperm in males. Within the testis, specialized cells known as Sertoli cells support the development of sperm cells through a process called spermatogenesis. This complex process occurs within the seminiferous tubules of the testis, where spermatogonia (the progenitor sperm cells) undergo several stages of division and maturation to produce mature spermatozoa.

The other structures mentioned serve different functions in the male reproductive system. The prostate gland contributes fluids to semen but is not involved in the actual production of sperm. The epididymis serves to store and mature the sperm after they are produced, while the vas deferens is responsible for transporting sperm away from the epididymis during ejaculation. Therefore, the role of the testis is uniquely central to the production, marking it as the correct answer.