If the pO 2 of oxygen in the alveoli is 104 mmHg and in the blood in alveolar capillaries is 40 mmHg, while the pCO 2 in the alveoli 40 mmHg and in the blood is 46 mmHg, which of the following will happen?

D: Dissolved gases will diffuse from where they are in high concentration to where they are in low concentration. Hence CO 2 can go from 46 mmHg to 40 mmHg and pO 2 can move from where it is at 104 mmHg to where it is at 40 mmHg. D is the only choice consistent with this.