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: Medicine
[{'content': 'In stable angina : \nSelect and explain. \nA. CK-MB is elevated, B. Troponin I is elevated, C. Myoglobin is elevated, D. The levels of cardiac markers remain unchanged', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer is D (The levels of cardiac markers remain unchanged)', 'role': 'assistant'}]