This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
[{'content': "A 68-year-old woman presented with unstable angina and underwent cardiac catheterization by radial access. There was difficulty advancing the guidewire; a brachial angiogram revealed the following. What is the diagnosis? \nSelect and explain. \nA. Takayasu's arteritis, B. Arteriovenous malformation, C. Brachial artery stenosis, D. Fibromuscular dysplasia", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer D. Fibromuscular dysplasiaThe correct answer is fibromuscular dysplasia. This right brachial angiography has a classic "string of beads" pattern consistent with fibromuscular dysplasia, a noninflammatory, nonatherosclerotic disorder of the blood vessels. Fibromuscular dysplasia is most commonly seen in the carotid and renal arteries but has been observed in nearly every arterial bed.', 'role': 'assistant'}]