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
To check disorder or patency of coronary artery circulation which technique is not recently used? 
Select and explain. 
A. Intravascular USG, B. C.T guided angiography, C. Echocardiography, D. USG
D: USG
Answer: D: USG 
Explanation: None