Deoxygenated blood entering the alveoli has dissolved oxygen with partial pressure of 40 mmHg, while alveolar air has oxygen present at a partial pressure of 90 mmHg. What will be the partial pressure of dissolved oxygen in blood that leaves the lungs?
A. 40 mmHg
B. 65 mmHg
C. 90 mmHg
D. 100 mmHg