Which of the following structures is included in the lower airway?

The lower airway consists of structures that are crucial for the conduction of air and the exchange of gases in the lungs. The trachea, bronchi, and alveoli are integral components of this system.

The trachea serves as the main airway passage from the larynx to the bronchi, allowing air to move into the lungs. The bronchi branch off the trachea into the left and right lungs, further dividing into smaller bronchioles. Alveoli, the tiny air sacs at the end of the bronchioles, are vital for gas exchange, facilitating the transfer of oxygen into the blood and carbon dioxide out of the blood.

The other options list structures associated with either the upper airway or parts of the respiratory system that do not fit the classification of the lower airway. The nasal passages, oropharynx, and larynx are part of the upper airway that serve functions involved in filtering, humidifying, and conducting air to the lower structures, while the pharynx, chest wall, and diaphragm refer to different aspects of the respiratory anatomy that do not specifically identify as part of the lower airway.