This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
[{'content': 'A 45-year-old woman who smokes is found to have a splenic artery aneurysm. It was most likely caused by: \nSelect and explain. \nA. Atherosclerosis, B. Trauma, C. Medial dysplasia, D. Pancreatitis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Splenic artery aneurysms in women are almost always caused by medial dysplasia of the artery. It may be the cause of rupture in pregnancy and can be life-threatening if not treated promptly by laparotomy. Aneurysms may be caused by atherosclerosis, trauma, and pancreatitis (when complicated by pseudocyst formation). Portal hypertension is not a cause of aneurysm.', 'role': 'assistant'}]