What is the partial pressure of carbon dioxide in alveolar air and in deoxygenated blood respectively?

• A. 50 mm Hg, 45 mm Hg
• B. 104 mm Hg, 45 mm Hg
• C. 45 mm Hg, 40 mm Hg
• D. 40 mm Hg, 45 mm Hg