Assertion `:-` Inspiration can occur if intra pulmonary pressure is less than the atmospheric pressure.
Reason `:-` Inspiration is initiated by the relaxation of diaphragm and external intercostal muscle.

Options

A. If both Assertion & Reason are True & the Reasonn is a correct explanation of the Assertion .
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Inspiration can occur if intrapulmonary pressure is less than the atmospheric pressure."
- This is true because air flows from an area of higher pressure (atmospheric pressure) to an area of lower pressure (intrapulmonary pressure). Therefore, for inspiration to occur, the pressure inside the lungs (intrapulmonary pressure) must be lower than the pressure outside (atmospheric pressure).

2. **Understanding the Reason**:
- The reason states that "Inspiration is initiated by the relaxation of the diaphragm and external intercostal muscles."
- This statement is incorrect. Inspiration is actually initiated by the contraction of the diaphragm and the external intercostal muscles, not their relaxation. When these muscles contract, the diaphragm flattens and the rib cage expands, creating a negative pressure in the thoracic cavity that allows air to flow into the lungs.

3. **Conclusion**:
- The assertion is true, while the reason is false. Therefore, the correct answer is that the assertion is true and the reason is false.

### Final Answer:
- Assertion: True
- Reason: False