Lungs are covered by

Options

A. Perichondrium
B. Pleural sac
C. Pericardium
D. Peristomium

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks what covers the lungs. We need to identify the correct anatomical structure from the given options.

2. **Analyzing the Options**:
- **Perichondrium**: This is the connective tissue that surrounds cartilage. It does not cover the lungs.
- **Pleural Sac**: This refers to the double-layered membrane surrounding the lungs, consisting of the parietal pleura and visceral pleura.
- **Pericardium**: This is the membrane that surrounds the heart, not the lungs.
- **Periosteum**: This is a layer of connective tissue that surrounds bones, which is also not related to the lungs.

3. **Identifying the Correct Answer**: The lungs are covered by the pleural sac, which consists of two layers:
- **Parietal Pleura**: The outer layer that is attached to the chest wall.
- **Visceral Pleura**: The inner layer that is attached to the lungs.

4. **Conclusion**: Based on the analysis, the correct answer to the question is **Pleural Sac** (Option B).