This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Heart & Pericardium, Subject name: Surgery
[{'content': 'Stenosis of which of the following vessels is associated with the highest patency rates following angioplasty or stenting? \nSelect and explain. \nA. Medial circumflex artery, B. Iliac artery, C. Superficial femoral artery, D. Popliteal artery', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Angioplasty and stenting of the iliac vessels has a patency rate of 75% at 5 years; PTA and stenting of all other vessels has a much lower patency than bypass procedures. The FDA has only approved illiac artery stenting.', 'role': 'assistant'}]