Which of the following components of blood fights infection?

Options

A. White blood cells
B. Platelets
C. Red blood cells
D. All of these

Answer

**Step-by-Step Solution:**

1. **Identify the Components of Blood**: Blood consists of several components, including red blood cells (RBCs), white blood cells (WBCs), and platelets.

2. **Understand the Function of Each Component**:
- **White Blood Cells (WBCs)**: Also known as leukocytes, these cells are primarily responsible for fighting infections and protecting the body against pathogens. They include various types such as basophils, neutrophils, eosinophils, monocytes, and lymphocytes.
- **Platelets**: These are also known as thrombocytes and are mainly involved in blood clotting. Their primary function is to prevent excessive blood loss during injuries.
- **Red Blood Cells (RBCs)**: Also known as erythrocytes, their main function is to transport oxygen throughout the body.

3. **Analyze the Options**:
- Option 1: White Blood Cells (WBCs) - Fight infections.
- Option 2: Platelets - Help in blood clotting, do not fight infections.
- Option 3: Red Blood Cells (RBCs) - Carry oxygen, do not fight infections.
- Option 4: All of the above - Incorrect since only WBCs fight infections.

4. **Conclusion**: Based on the functions of each component, the correct answer to the question "Which of the following components of blood fights infection?" is **White Blood Cells (WBCs)**.

**Final Answer**: White Blood Cells (WBCs) fight infection.

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