This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aneurysms, Subject name: Surgery
[{'content': 'Most common cause of pseudoaneurysm - \nSelect and explain. \nA. iv drug abuse, B. Trauma, C. Congenital, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e.,Trauma", 'role': 'assistant'}]