Final answer:
The seminal vesicles are responsible for producing the majority of the bulk of semen, contributing roughly 60 percent. The correct answer is option a).
Step-by-step explanation:
Most of the bulk of semen is made by the seminal vesicles. The seminal vesicles, the prostate gland, and the bulbourethral glands are three critical accessory glands of the male reproductive system that contribute to the composition of semen.
However, it is the seminal vesicles that contribute the most, accounting for approximately 60 percent of the bulk of semen. The fluid produced by the seminal vesicles is thick, yellowish, and alkaline, which is crucial for providing an environment conducive for sperm motility by countering the acidity of the vaginal environment.
The seminal vesicles account for 60 percent of the bulk of semen, producing a solution that is thick, yellowish, and alkaline. The prostate gland and bulbourethral gland also contribute to the production of semen. This seminal fluid also contains important substances such as mucus, fructose, a coagulating enzyme, ascorbic acid, and prostaglandins.