Which of the following is a chronic respiratory in which alveolar walls are damaged due to which respiratory surface is decreased ?

Options

A. Asthma
B. Emphysema
C. Silicosis
D. Pneumonia

Answer

To solve the question regarding which chronic respiratory condition involves damage to the alveolar walls, leading to a decrease in respiratory surface area, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify a chronic respiratory disease characterized by damage to the alveolar walls, resulting in a reduced respiratory surface area.

2. **Analyze the Options**:
- **Asthma**: This condition is primarily an inflammatory disease affecting the bronchi and bronchioles, leading to wheezing and difficulty in breathing. It does not primarily damage alveolar walls.
- **Emphysema**: This is a chronic lung condition where the alveolar walls are damaged, leading to a decrease in the surface area available for gas exchange. This is often associated with cigarette smoking.
- **Silicosis**: An occupational lung disease caused by inhaling silica dust, which can lead to lung damage but is not primarily characterized by the destruction of alveolar walls.
- **Pneumonia**: This is an infection of the lungs that affects the alveoli but does not primarily involve chronic damage to the alveolar walls.

3. **Identify the Correct Answer**: Among the options analyzed, **Emphysema** is the only condition that fits the description of a chronic respiratory disease where the alveolar walls are damaged, leading to decreased respiratory surface area.

4. **Conclusion**: The correct answer to the question is **Emphysema**.

### Final Answer:
**Emphysema**

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