_____ is known as the grveyard of RBCs.

Options

A. Liver
B. Spleen
C. Pancreas
D. Bone marrow

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the organ known as the "graveyard of RBCs" (red blood cells). This implies we need to identify where RBCs are destroyed or discarded in the body.

2. **Identifying the Options**: The options provided are:
- Liver
- Spleen
- Pancreas
- Bone Marrow

3. **Function of RBCs**: RBCs are crucial for transporting oxygen in the blood and are formed in the bone marrow.

4. **Lifespan of RBCs**: The average lifespan of RBCs is approximately 120 days. After this period, they need to be removed from circulation.

5. **Location of RBC Destruction**: The organ responsible for the destruction of old and damaged RBCs is the spleen. It filters the blood and removes these cells.

6. **Eliminating Incorrect Options**:
- **Liver**: While the liver has many functions, it is not primarily responsible for the destruction of RBCs.
- **Pancreas**: This organ is involved in digestion and blood sugar regulation, not in the destruction of RBCs.
- **Bone Marrow**: This is where RBCs are produced, not destroyed.

7. **Conclusion**: Based on the information, the correct answer is the spleen, which is known as the "graveyard of RBCs" due to its role in filtering and destroying old red blood cells.

**Final Answer**: Spleen

---