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: Unknown
[{'content': 'In exhaled air, normal pCO2 pressure is: \nSelect and explain. \nA. 36 mm Hg, B. 27 mm Hg, C. 40 mm Hg, D. 17 mm Hg', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Refer: Ganong’s Review of Medical Physiology, 24th edition, pg no: 635)', 'role': 'assistant'}]