Question

tiny air sacs in the lungs that allow for the exchange of oxygen and carbon dioxide

Explanation:

Alveoli are tiny air sacs in the lungs. They have thin walls and a large surface area, which allows for efficient gas exchange. Oxygen from the inhaled air diffuses across the alveolar walls into the bloodstream, while carbon dioxide from the blood diffuses into the alveoli to be exhaled. Bronchi are the main air passages into the lungs, bronchioles are smaller branches of the bronchi, and the trachea (windpipe) is the tube that connects the throat to the bronchi.

Answer:

D. alveoli