The correct answer to the question is: C. Alveoli.
Gas exchange of carbon dioxide (CO2) for oxygen occurs between the capillaries and the alveoli in the lungs. The alveoli are tiny air sacs located at the end of the bronchioles where the actual exchange of gases takes place during the process of respiration.
When we breathe in, oxygen enters the alveoli and diffuses into the surrounding capillaries, where it binds to hemoglobin in red blood cells for transport to tissues throughout the body. At the same time, carbon dioxide produced by cellular metabolism diffuses from the capillaries into the alveoli to be exhaled when we breathe out. This exchange of gases is crucial for maintaining the body's oxygen supply and removing waste carbon dioxide.
