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': 'To check disorder or patency of coronary artery circulation which technique is not recently used? \nSelect and explain. \nA. Intravascular USG, B. C.T guided angiography, C. Echocardiography, D. USG', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]