Which of the following can best be compared to soldiers?

Options

A. Lungs
B. Capillaries
C. Red blood cells
D. White blood cells

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which of the given options can be best compared to soldiers. This implies we are looking for a component of the body that plays a protective or defensive role, similar to how soldiers protect a nation.

2. **Analyzing the Options**: The options provided include:
- Lungs
- Capillaries
- Red Blood Cells
- White Blood Cells

3. **Evaluating Each Option**:
- **Lungs**: The primary function of the lungs is to facilitate gas exchange (oxygen and carbon dioxide). They do not have a defensive role, so they cannot be compared to soldiers.
- **Capillaries**: These are small blood vessels that connect arteries and veins, primarily involved in the exchange of substances between blood and tissues. They do not provide defense, so they are not comparable to soldiers.
- **Red Blood Cells**: Their main function is to transport oxygen throughout the body. While essential for survival, they do not have a protective function, making them unsuitable for comparison to soldiers.
- **White Blood Cells**: These cells are crucial for the immune system. They protect the body against infections and foreign invaders, functioning similarly to soldiers who defend a country.

4. **Conclusion**: Based on the analysis, white blood cells are the best comparison to soldiers due to their role in providing immunity and defending the body against pathogens. Therefore, the correct answer is **white blood cells**.

### Final Answer:
White Blood Cells can best be compared to soldiers.

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