Describe the process of inhalation and exhalation in humans.

A. During inhalation, the chest cavity decreases in volume, while it increases in volume during exhalation.

B. Inhalation involves the movement of the ribs upward and outward, while exhalation involves the movement of the ribs downward and inward.

C. The diaphragm relaxes and moves downward during inhalation, while it contracts and moves upward during exhalation.

D. The diaphragm contracts and moves downward during inhalation, while it relaxes and moves upward during exhalation.