The average lifespan is the highest for :

Options

A. RBC
B. Neutrophils
C. Eosinophils
D. Basophils

Answer

To determine which blood cell has the highest average lifespan among the options given (RBC, neutrophils, eosinophils, basophils), we can analyze the lifespan of each cell type step by step.

### Step 1: Identify the Lifespan of Each Cell Type
- **RBC (Red Blood Cells)**: The average lifespan of RBCs is approximately **120 days**.
- **Neutrophils**: Neutrophils have a lifespan of about **5 to 135 hours** when inactive, and **1 to 2 days** when active. This translates to roughly **0.2 to 5.6 days**.
- **Eosinophils**: Eosinophils have a lifespan of about **2 to 5 days**.
- **Basophils**: Basophils have a lifespan of approximately **1 to 2 days**.

### Step 2: Compare the Lifespan of Each Cell Type
Now, let's compare the average lifespans:
- RBCs: 120 days
- Neutrophils: 0.2 to 5.6 days
- Eosinophils: 2 to 5 days
- Basophils: 1 to 2 days

### Step 3: Determine the Highest Lifespan
From the comparison:
- The RBCs have a significantly longer lifespan (120 days) compared to the other white blood cells (neutrophils, eosinophils, and basophils), which only have lifespans ranging from a few days to a week at most.

### Conclusion
Thus, the average lifespan is the highest for **RBCs (Red Blood Cells)**.

### Final Answer
**RBC (Red Blood Cells)** have the highest average lifespan among the options provided.

---