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 syndrome X, patients have all of the following except - \nSelect and explain. \nA. Angina like chest pain, B. Ischemic ST segment depression, C. Abnormal coronary arteriogram, D. Excellent prognosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]