Final answer:
The seminal vesicle (C) is the gland that secretes a fluid containing fructose, providing an energy source for sperm.
Step-by-step explanation:
The gland that secretes a fluid containing fructose is the seminal vesicle (C). The seminal vesicles are two glands located within the pelvis that secrete an alkaline fluid, which makes up about 70% of semen. This fluid provides sperm with the nutrients they need to survive and be motile in the female reproductive tract, with fructose being a key energy source for the sperm. On the other hand, the prostate gland contributes roughly 30% to the seminal fluid and is known for its high concentration of zinc but not specifically for fructose content. The bulbourethral glands, also known as Cowper's glands, secrete a pre-ejaculate fluid that helps lubricate the urethra and neutralize any acidic urine, but do not contribute fructose to the semen.
It should be noted that the prostate gland is not located in the testes, as erroneously stated in the provided reference. Instead, it is situated anterior to the rectum at the base of the bladder and surrounds the prostatic urethra.