This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System Pa 2, Subject name: Physiology
[{'content': 'At the altitude of 6500 meters, the atmospheric pressure is 347 mmHg. What is the inspired PO2. \nSelect and explain. \nA. 73 mm Hg, B. 63 mm Hg, C. 53 mm Hg, D. 83 mm Hg', 'role': 'user'}, {'content': 'Answer: B \nExplanation: According to law of paial pressures : Pressure exeed by a gas in a mixture is directly propoional to its concentration in the mixture. In inspired gases; 20 % = O2 78% = N2 PH2O = 47 mmHg (air humidified with inspiration) =347 - 47 = 300 mmHg = gaseous component', 'role': 'assistant'}]