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': 'In which of the following conditions the respiratory muscles are relaxed? \nSelect and explain. \nA. Residual volume, B. Functional residual capacity, C. Expiratory reserve volume, D. Inspiratory reserve volume', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The volume of gas remaining in the lungs after a full expiratory effo.Ref: Ganong&;s Review of Medical Physiology; 24th edition; page no: 629', 'role': 'assistant'}]