This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Which is true about carotid stenosis - \nSelect and explain. \nA. Ipsilateral hemiplegia by embolism of MCA, B. Bruit indicates severity of steno sis, C. Common in External carotid artery, D. Aspirin reduces risk of TIA', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]