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: Anatomy
The narrowest pa of the ureter is at the: 
Select and explain. 
A. Uretero - pelvic junction, B. Hiac vessel crossing, C. Pelvic ureter, D. Uretero - vesicle junction
D: Uretero - vesicle junction
Answer: D: Uretero - vesicle junction 
Explanation: D i.e. Uretero - vesicle junctionAt the level of ischial spine ureter changes its direction from down-backward to forward - medially but there is no constriction. The narrowest pa of ureter is uretero- vesicle junctions