A person normally passively inhales and exhales 500 mL of air. This is the .......

Options

A. Tidal volume
B. Inspiratory capacity
C. Residual volume
D. Vital capacity

Answer

To solve the question, "A person normally passively inhales and exhales 500 mL of air. This is the .......", we need to identify the correct term that describes the volume of air inhaled and exhaled during normal breathing.

### Step-by-Step Solution:

1. **Understanding the Question**: The question states that a person inhales and exhales 500 mL of air passively. This means we are looking for a specific term that describes this volume of air during normal, relaxed breathing.

2. **Identifying the Options**: The options provided are:
- A) Tidal volume
- B) Respiratory capacity
- C) Residual volume
- D) Vital capacity

3. **Analyzing Each Option**:
- **A) Tidal Volume**: This term refers to the amount of air that is inhaled or exhaled during a normal respiratory cycle at rest. It typically ranges from 500 to 550 mL in a healthy individual. Since the question mentions 500 mL, this matches the definition of tidal volume.

- **B) Respiratory Capacity**: This term generally refers to the total amount of air that can be inhaled or exhaled, which includes various volumes. It is not a specific volume of air like tidal volume.

- **C) Residual Volume**: This is the volume of air that remains in the lungs after a forceful expiration. It does not relate to the volume of air inhaled or exhaled during normal breathing, making it an incorrect option.

- **D) Vital Capacity**: This is the maximum amount of air that can be exhaled after a maximum inhalation. It is significantly larger than 500 mL (usually 3 to 5 liters), so this option is also incorrect.

4. **Conclusion**: Based on the definitions and the analysis of each option, the correct answer is **A) Tidal Volume**. This is the volume of air that is inhaled or exhaled during normal, passive breathing, which is 500 mL in this case.

### Final Answer:
The correct answer is **A) Tidal Volume**.