This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aortic Imaging, Subject name: Radiology
[{'content': 'Best investigation for diagnosing abdominal aortic aneurysm is? \nSelect and explain. \nA. USG, B. CT angiography, C. Classical radiography, D. Non contrast CT scan', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. (b) CT angiographyRef. Interventional cardiology by sinha, p 134, Harrison's 17/e, chapter 242", 'role': 'assistant'}]