Assertion :- Lymph is the filtered blood from capillaries, which is rich in oxygen, but devoid of RBC.
Reason:- RBC can filter out due to small diameters of fenestra of capillary, but O2 can not do so.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both assertion and reason are false

Answer

To solve the question, we will analyze the assertion and reason step by step.

### Step 1: Understanding the Assertion
The assertion states that "Lymph is the filtered blood from capillaries, which is rich in oxygen, but devoid of RBC."

- **Explanation**: Lymph is indeed derived from blood plasma that leaks out of capillaries. It contains nutrients, waste products, and oxygen, but it does not contain red blood cells (RBCs) because RBCs are too large to pass through the capillary walls.

### Step 2: Understanding the Reason
The reason states that "RBC can filter out due to small diameters of fenestra of capillary, but O2 cannot do so."

- **Explanation**: This statement is incorrect. While it is true that the fenestra (small pores) in capillaries allow certain substances to pass through, RBCs are too large to pass through these openings. Oxygen, being a small molecule, can easily diffuse through the capillary walls into the lymph.

### Step 3: Evaluating the Relationship Between Assertion and Reason
Now we need to determine if the reason correctly explains the assertion.

- The assertion is true: Lymph is filtered blood that is rich in oxygen and devoid of RBCs.
- The reason is false: RBCs do not filter out due to the small diameters of fenestra; rather, they are simply too large to pass through.

### Conclusion
Based on the analysis:
- The assertion is true.
- The reason is false.

Thus, the correct answer is that the assertion is true but the reason is false.

### Final Answer
The correct option is: **Assertion is true, but Reason is false.**

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