Answer:
B) lung volume cannot increase as much and so air pressure cannot decrease
Step-by-step explanation:
If air will enter the chest cavity then lung will not find proper space to expand. As we all know that pressure and volume both have inverse relation that means an increase in volume leads to decrease in pressure. In short, if volume increases, pressure decreases.
In normal condition, if air enters lungs, the lungs withstand the increased air pressure by expanding themselves. Expansion of lungs volume reduce the pressure which air exerts on them.
But, in pneumothorax condition since the chest cavity where lungs are situated is filled with air so when air will enter the lungs, the lungs will not find required space to expand and air pressure will not decrease leading to short and shallow inspiration.