Spot the odd one out from the following structures with reference to the male reproductive system.

Options

A. Rete testis
B. Epididymis
C. Vasa efferentia
D. Isthmus

Explanation

To solve the question of spotting the odd one out from the structures related to the male reproductive system, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structures**: The four options given are:
- A) Retetestis
- B) Epididymis
- C) Vasa Efferentia
- D) Isthmus

2. **Understand Each Structure**:
- **Retetestis**: This is a network of tubules located in the testis that collects sperm from the seminiferous tubules.
- **Epididymis**: This is a coiled tube where sperm mature and are stored, located on the surface of the testis.
- **Vasa Efferentia**: These are the ducts that transport sperm from the rete testis to the epididymis.
- **Isthmus**: This is a part of the female reproductive system, specifically a section of the fallopian tube that connects the ampulla to the uterus.

3. **Categorize the Structures**:
- The first three structures (Retetestis, Epididymis, and Vasa Efferentia) are all components of the male reproductive system.
- The Isthmus, however, is part of the female reproductive system.

4. **Identify the Odd One Out**: Since the Isthmus is not part of the male reproductive system, it is the odd one out.

5. **Conclusion**: The correct answer is D) Isthmus.