**Core Concept**
The epididymis is a critical structure in the male reproductive system, and its surface is characterized by a unique network of veins and arteries. This network plays a vital role in regulating temperature, providing oxygenation, and facilitating the maturation of sperm.

**Why the Correct Answer is Right**
The correct answer is the pampiniform plexus, a complex network of veins that surrounds the testicular arteries and lies on the surface of the epididymis. This plexus is composed of multiple layers of interconnected veins that help to regulate the temperature of the testes, ensuring optimal conditions for sperm maturation. The pampiniform plexus is a critical component of the spermatic cord and is essential for maintaining testicular function.

**Why Each Wrong Option is Incorrect**
- **Option A:** The cremasteric artery is not directly associated with the epididymis; it is a branch of the inferior epigastric artery and supplies the cremaster muscle.
- **Option B:** The deferential artery is a branch of the superior vesical artery and supplies the vas deferens, not the epididymis.
- **Option C:** The testicular artery is responsible for supplying oxygenated blood to the testes, but it is not the network of veins and arteries that lies on the surface of the epididymis.

**Clinical Pearl / High-Yield Fact**
The pampiniform plexus is a critical structure that can be compromised in conditions such as varicocele, which can lead to testicular atrophy and reduced fertility.

**Correct Answer:** C. Pampiniform plexus.