This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aerial disorders, Subject name: Surgery
[{'content': "Drug used for Buerger's disease: \nSelect and explain. \nA. Xanthinol nicotinate, B. Propranolol, C. CCBs, D. All of the above", 'role': 'user'}, {'content': "Answer: A \nExplanation: Xanthinol Nicotinate Xanthinol nicotinate (or xanthinol niacinate or complamina) is a vasodilatorQ. It is a combination of xanthinol and niacin (nicotinic acid) This vasodilator is used in the treatment of Raynaud's phenomenon and Buerger's disease. All other forms of pharmacologic treatment have been generally ineffective in the treatment of Buerger's disease, including, steroids, calcium channel blockers, reserpine, vasodilators, antiplatelet drugs.", 'role': 'assistant'}]