I believe the answer is a.
Answer:
Explanation:
inspiration 1. inspiratory muscles contract. ...
inspiration 2. thoracic cavity volume increases.
inspiration 3. lungs are stretched. ...
inspiration 4. intrapulmonary pressure drops.
inspiration 5. air flows into lungs down pressure gradient until pulmonary pressure is 0.
Answer:
D is the answer to this question
The answer would be toxin