Which of the Following Conditions Are Determinants of Gas Exchange

Multiple Choice

Which of the following conditions are determinants of gas exchange across the membrane?
1) Amount of oxygen in the blood
2) Thickness of the alveolar-capillary membrane
3) Diffusion coefficient of carbon monoxide in the lungs
4) Surface area of the membrane

A) 1 and 4
B) 2 and 3
C) 1, 2, and 3
D) 2, 3, and 4