Lungs are protected by

Options

A. pericardium
B. mesocardium
C. myocardium
D. pleura

Answer

### Step-by-Step Solution:

1. **Identify the Structure Protecting the Lungs**: The primary structure that protects the lungs is the rib cage. The rib cage is a bony structure made up of 12 pairs of ribs that encase the lungs and provide physical protection.

2. **Understanding the Rib Cage**: The rib cage is not only composed of ribs but also connects to the spine at the back. This connection provides additional support and protection to the lungs.

3. **Role of the Pleura**: In addition to the rib cage, the lungs are also protected by a membrane known as the pleura. The pleura is a double-layered membrane that surrounds the lungs and provides a protective barrier.

4. **Reviewing Incorrect Options**:
- **Option 1 - Pericardium**: This is a membrane that surrounds the heart, not the lungs.
- **Option 2 - Mesocardium**: This is a double layer that supports the embryonic heart, also not related to the lungs.
- **Option 3 - Myocardium**: This is the muscular layer of the heart, which is again not related to lung protection.

5. **Conclusion**: Based on the analysis, the correct answer to the question "Lungs are protected by" is the pleura, as it is the membrane specifically associated with lung protection.