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: Anatomy
[{'content': 'The left subclan aery is a branch of : \nSelect and explain. \nA. Bracheocephalic trunk, B. Ascending aoa, C. Arch of aoa, D. Left common carotid', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Arch of aoa', 'role': 'assistant'}]