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': 'The volume of gas in the lungs at the end of normal expiration is: \nSelect and explain. \nA. Expiratory reserve volume, B. Functional residual capacity, C. Residual volume, D. Inspiratory reserve volume', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The volume of the air remaining in the lungs after normal expiration is Functional Residual Volume (FRV).\nThe volume of the air remaining in the Lungs after forced expiration is Residual Volume (RV).', 'role': 'assistant'}]