Lungs do not enclose

Options

A. Bronchi
B. Trachea
C. Bronchioles
D. Alveoli

Answer

To solve the question "Lungs do not enclose," we need to identify which of the given options is not a part of the lungs. The options provided are:

1. Bronchi
2. Trachea
3. Bronchioles
4. Alveoli

### Step-by-Step Solution:

1. **Understanding the Options**:
- **Bronchi**: These are the large air passages that branch from the trachea into the lungs. They are indeed part of the lungs.
- **Trachea**: This is commonly known as the windpipe. It is the main airway that leads from the throat to the bronchi. It is not enclosed within the lungs.
- **Bronchioles**: These are smaller branches of the bronchi that lead to the alveoli. They are part of the lung structure.
- **Alveoli**: These are tiny air sacs in the lungs where gas exchange occurs. They are also part of the lungs.

2. **Identifying the Correct Answer**:
- From the analysis, we can see that the bronchi, bronchioles, and alveoli are all parts of the lungs. However, the trachea is not enclosed within the lungs; it is the initial part of the respiratory tract that leads into the lungs.

3. **Conclusion**:
- Therefore, the correct answer to the question "Lungs do not enclose" is **Trachea**.

### Final Answer:
**Trachea** (Option 2) is not enclosed in the lungs.

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