Dead space air is the volume of air that:

 # Dead space air is the volume of air that:

A. Remains in the lungs after maximal expiration.

B. Is exchanged during a normal breath.

C. Occupies the conducting airways and does not participate in gas exchange.

D. Can be forcefully inhaled after a normal inspiration.

The correct answer is C. Occupies the conducting airways and does not participate in gas exchange.

Explanation: Dead space air refers to the volume of air that fills the conducting airways (such as the trachea and bronchi) during breathing but does not participate in gas exchange because it does not reach the alveoli, where oxygen and carbon dioxide exchange occurs.