The partial pressure of oxygen in the alveoli of the lungs is Less than that in the blood, Equal to that in the blood, Less than that of carbon dioxide, or More than that in the blood?

Alveoli are the site of gaseous exchange and have the higher partial pressure of oxygen than that of blood. Blood is rich in carbon dioxide at cell and tissue level due to cellular respiration. The higher partial pressure of oxygen in alveoli allow diffusion of oxygen into the blood. Therefore, the correct answer is option D.