- A Inspiratory reserve volume
- B Tidal volume
- C Residual volume
- D Vital capacity
Correct answer: C. Residual volume
Explanation: Residual volume is the air that always remains in the lungs after maximum exhalation, preventing the lungs from collapsing.
Concept context
The mechanics of breathing, lung volumes, gas transport in blood, the Bohr effect, and respiratory regulation.