This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'In a normal resting person, breathing air at sea level with RQ of 0.8, Pa CO2 of 40mm Hg, Pi O2 of 149 mm Hg and Fi O2 of 21 %. Calculate alveolar partial pressure of oxygen \nSelect and explain. \nA. 100 mm Hg, B. 90 mm Hg, C. 120 mm Hg, D. 80 mm Hg', 'role': 'user'}, {'content': 'Answer: A \nExplanation: From Alveolar Gas Equation,\nAlveolar partial pressure of Oxygen is', 'role': 'assistant'}]