**Core Concept**
The question is testing the student's knowledge of the male reproductive system, specifically the components involved in sperm transport. The epididymis, vas deferens, seminal vesicles, and prostate gland all play roles in sperm maturation, storage, and transport.

**Why the Correct Answer is Right**
The correct answer is the seminal vesicles. The seminal vesicles are a pair of glands that contribute a significant portion of the fluid to the ejaculate, providing nutrients and fructose to support sperm metabolism. However, they do not conduct spermatozoa. In contrast, the epididymis stores and matures sperm, the vas deferens transports sperm, and the prostate gland contributes additional secretions to the ejaculate.

**Why Each Wrong Option is Incorrect**
* **Option A (Epididymis):** The epididymis plays a crucial role in sperm maturation and storage, but it does conduct spermatozoa.
* **Option B (Vas Deferens):** The vas deferens is a muscular tube that transports sperm from the epididymis to the prostate gland, so it does conduct sperm.
* **Option C (Prostate Gland):** The prostate gland contributes secretions to the ejaculate, but it does not conduct spermatozoa.
* **Option D:** Not provided, but assuming it was a blank, the student should have chosen one of the above options.

**Clinical Pearl / High-Yield Fact**
The male reproductive system is complex, and understanding the roles of each component is essential for diagnosing and managing conditions such as infertility, erectile dysfunction, and prostate disease.

**Correct Answer:** C. Prostate Gland. The prostate gland contributes secretions to the ejaculate, but it does not conduct spermatozoa.