This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
[{'content': 'Normal intrapleural pressure at the sta/beginning of inspiration is----- cm of H2O. \nSelect and explain. \nA. -7.5, B. -5, C. -2, D. -0.5', 'role': 'user'}, {'content': 'Answer: B \nExplanation: During inspiration, the diaphragm and external intercostal muscles contract, increasing the volume of the thoracic cavity. This causes the intrapleural pressure to become more negative, which increases the transpulmonary pressure, causing the lungs to expand Ref: guyton and hall textbook of medical physiology 12 edition page number:316,317,318', 'role': 'assistant'}]