In the Lung's Alveoli, There Are Four Gases Mixed Together

Multiple Choice

In the lung's alveoli, there are four gases mixed together: oxygen, carbon dioxide, nitrogen, and water vapor. At a normal barometric pressure of 760 mm Hg, alveolar O₂ exerts a partial pressure of 100 mm Hg, CO₂ 40 mm Hg, and water vapor 47 mm Hg. What is the alveolar partial pressure of nitrogen?

A) 187 mm Hg
B) 713 mm Hg
C) 660 mm Hg
D) 573 mm Hg