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': 'Normal intrapleural pressure during the start of inspiration is\t ________ mm of Hg. \nSelect and explain. \nA. -2, B. -5, C. 0, D. -7', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]