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': "Aortic regurgitation may be associated with all of the following except - \nSelect and explain. \nA. Ankylosing Spondylitis, B. Marfan's Syndrome, C. Dissection of the aorta, D. Polyarteritis nodosa", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]