Which of the acts as middle man?
(a) W.B.C.
(b) Plasma
(c) Blood
(d) Lymph

Options

A. W.B.C.
B. Plasma
C. Blood
D. Lymph.

Answer

To determine which of the options acts as a middleman, we need to analyze each option in the context of their roles in the circulatory and lymphatic systems.

### Step-by-Step Solution:

1. **Understand the Options**: We have four options to consider:
- (a) W.B.C. (White Blood Cells)
- (b) Plasma
- (c) Blood
- (d) Lymph

2. **Define Each Component**:
- **W.B.C. (White Blood Cells)**: These are cells that are part of the immune system and help the body fight infections. They do not function as a middleman.
- **Plasma**: This is the liquid component of blood that carries cells, nutrients, hormones, and waste products. While it is essential for transport, it does not act as a middleman.
- **Blood**: This is the fluid that circulates in the body, consisting of red blood cells, white blood cells, platelets, and plasma. Blood itself does not act as a middleman.
- **Lymph**: This is a fluid that is part of the lymphatic system. It is formed from interstitial fluid and contains white blood cells. Lymph acts as a middleman by collecting excess fluid from tissues and transporting it back to the bloodstream.

3. **Identify the Middleman**: Among the options, lymph is the only component that acts as a middleman. It collects interstitial fluid from tissues and eventually returns it to the bloodstream, mixing with blood at the subclavian veins.

4. **Conclusion**: Therefore, the correct answer is (d) Lymph.

### Final Answer:
(d) Lymph

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