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': 'Energy expenditure during normal breathing \nSelect and explain. \nA. 25% - 50% of total energy spent, B. 50% - 75% of total energy spent, C. 15% - 20% of total energy spent, D. 2% - 3% of total energy spent', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]