during exhalation, the ribs become depressed as the intercostal muscle relax - this the lung volume decreases which increases the alveolar pressure. what does this cause

The correct answer will be option A.

Explanation:

Exhalation is a  mechanism of breathing which exhales out the gases from the lungs to the atmosphere.

During the exhalation process the thoracic volume decreases which decrease the lung volume. This decreases alveolar volume.  Due to this decrease in alveolar volume the intra- alveolar pressure increases above atmospheric pressure up to +2 cm of H₂O which results in the release of the gas or air out of the lungs.

Thus, option A is the correct answer.

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