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': 'Preferred biochemical markers in patients presenting with myocardial infarction September 2008 \nSelect and explain. \nA. Myoglobin, B. Cardiac specific Troponins, C. CK-MB, D. All of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: As. B: Cardiac specific Troponins Creatine kinase (CK) muscle and brain (CK-MB) mass and myoglobin measurements were the standard up to the mid-1990s, when assays for the cardiac-specific isoforms of troponin I and troponin T became available. They are now the preferred biochemical markers. They may rise to levels more than 20 times higher than the upper reference limit. Their levels may remain elevated for 7-10 days after STEMI', 'role': 'assistant'}]