This structure contributes acidic liquid to semen. Cowper’s glandseminal vesiclesvas deferensprostate

The prostate contributes a slightly acidic fluid to semen. Seminal vesicles produce a more alkaline fluid, while Cowper’s glands secrete mucus and the vas deferens transports sperm. Therefore, the correct choice is prostate.

AI-written and checked against the verified answer.