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': "A raised serum creatinine phosphokinase level in unusual in - \nSelect and explain. \nA. Acute alcoholic myopathy, B. Viral polymyositis, C. Myopathy of cushing's syndrome, D. Duchenne's muscular dystrophy", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]