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 arch of aorta lies in the ---- mediastinum - \nSelect and explain. \nA. Posterior, B. Anterior, C. Middle, D. Superior', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Arch of aorta lies in superior mediastinum.', 'role': 'assistant'}]