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: Radiology
Which radiological procedure is used for studying vesico-ureteric reflux? 
Select and explain. 
A. Ascending pyelogram, B. Cystogram, C. Intravenous urogram, D. Micturition cystourethrogram
D: Micturition cystourethrogram
Answer: D: Micturition cystourethrogram 
Explanation: The diagnosis of vesico ureteric reflux is made using micturition cystourethrogram. Other techniques used in diagnosing vesico ureteric reflux are simple or delayed cystography or voiding cinefluoroscopy. In a case of vesico ureteral reflux, cystogram may show one of the following findings: Persistently dilated lower ureter, areas of dilatation in the ureter, ureter visualized throughout its entire length shows, presence of hydroureteronephrosis with a narrow juxtavesical ureteral segment or changes of healed pyelonephritis. Ref: Smith's General Urology, 17e, Chapter 12