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
In stable angina - 
Select and explain. 
A. CK-MB is elevated, B. Troponin I is elevated, C. Myoglobin is elevated, D. The levels of cardiac markers remain unchanged
D: The levels of cardiac markers remain unchanged
Answer: D: The levels of cardiac markers remain unchanged 
Explanation: None