**Core Concept**
The production of fructose in the female reproductive system is related to the presence of male seminal fluid, which contains fructose as an energy source for sperm. This concept highlights the importance of forensic analysis in rape cases.

**Why the Correct Answer is Right**
Fructose is a vital component of semen, serving as a source of energy for sperm motility. The seminal vesicles, a pair of glandular organs located behind the bladder in males, are responsible for producing the majority of the fluid that makes up semen. This fluid, which includes fructose, is essential for sperm viability and function. In the context of a rape case, the presence of fructose in vaginal fluids can be used as evidence of seminal fluid.

**Why Each Wrong Option is Incorrect**
* **Option A:** The prostate gland contributes to the production of seminal fluid but is not the primary source of fructose.
* **Option B:** The epididymis is involved in sperm maturation and storage but is not responsible for fructose production.
* **Option D:** The testes produce sperm cells but are not directly involved in the production of seminal fluid or fructose.

**Clinical Pearl / High-Yield Fact**
The presence of fructose in vaginal fluids can be a valuable indicator of sexual assault, as it is a component of semen. However, its presence does not necessarily prove consent or lack thereof.

**Correct Answer:** C. Seminal vesicles.