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': 'Most common cause of Aortic dissection - \nSelect and explain. \nA. Hypertension, B. DM, C. Trauma, D. Marfan syndrome', 'role': 'user'}, {'content': "Answer: A \nExplanation: More than 90% of dissections occur in men between the age of 40 and 60 with antecedent hypertension. Other causes of dissection.\nMarfan syndrome causing cystic medial necrosis (second most common).\nEhlers - Danlos syndrome.\nInflammatory aortitis → Takayasu's disease, Giant cell arteritis.\nCoarctation of aorta.\nNormal woman during third trimester of pregnancy.\nCongenital bicuspid aortic valve.", 'role': 'assistant'}]