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: Pathology
[{'content': 'Characterstic CVS leison in syphils is - \nSelect and explain. \nA. Aneurysm of arch of aoa, B. Aoic ring dilatation, C. Medial necrosis, D. All', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Aoic ring dilatation Syphilitic aoitis usually affects the proximal ascending aoa, paicularly the aoic root, resulting in aoic dilatation and aneurism formation.", 'role': 'assistant'}]