Life of RBC in human blood is

Options

A. 30 days
B. 60 days
C. 120 days
D. 15 hrs

Explanation

To determine the lifespan of red blood cells (RBCs) in human blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to find out the lifespan of red blood cells in human blood from the given options: 30 days, 60 days, 120 days, or 15 hours.

2. **Identify the Full Form of RBC**: RBC stands for Red Blood Cells. They are crucial components of blood responsible for transporting oxygen throughout the body.

3. **Research the Lifespan of RBCs**: The lifespan of red blood cells is a well-documented fact in human physiology.

4. **Recall the Lifespan**: It is known that the average lifespan of RBCs in human blood is approximately 120 days.

5. **Compare with Other Blood Cells**: While considering RBCs, it's also useful to note that white blood cells (WBCs) have a shorter lifespan, typically ranging from 20 to 30 days, which highlights the longevity of RBCs compared to WBCs.

6. **Select the Correct Option**: Based on the information gathered, the correct answer to the question about the lifespan of RBCs in human blood is 120 days.

### Final Answer:
The lifespan of RBCs in human blood is approximately **120 days**.

---