This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Choose the appropriate lettered site or structure in this CT scan of the thorax from a 42-year old man who complains of chest pain and breathing problems. His electrocardiogram shows left ventricular hypertrophy. The left coronary artery arises from which structure? \nSelect and explain. \nA. A, B. B, C. C, D. D', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (c) The right and left coronary arteries arise from the ascending aorta', 'role': 'assistant'}]