Average life span of RBC and blood platelets respectively are  

Options

A. 100, 5-9 days
B. 200, 15-19 days
C. 120, 5-9 days
D. 180, 20-30 days

Answer

To determine the average lifespan of red blood cells (RBCs) and blood platelets, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Lifespan of RBCs**:
- Red blood cells (RBCs) are responsible for transporting oxygen throughout the body.
- The average lifespan of RBCs is approximately **120 days**.

2. **Identify the Lifespan of Blood Platelets**:
- Blood platelets are crucial for blood clotting. They help prevent excessive bleeding when there is an injury.
- The average lifespan of blood platelets is about **5 to 9 days**.

3. **Combine the Lifespan Information**:
- Therefore, the average lifespan of RBCs is **120 days** and the average lifespan of blood platelets is **5 to 9 days**.

4. **Select the Correct Option**:
- From the provided options, the only one that matches our findings is **120 days for RBCs and 5 to 9 days for blood platelets**.

### Final Answer:
- The average lifespan of RBCs is **120 days** and the average lifespan of blood platelets is **5 to 9 days**.

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