Kidney Stones, or Renal Calculi, Tend to Lodge Most Often

Kidney stones, or renal calculi, tend to lodge most often in places where their pathway out of the body tends to narrow. All of these are regions where the ureter narrows and kidney stones may lodge except

A) where the renal pelvis narrows into the ureter.
B) at the urachus of the ureter.
C) at the point where the ureters enter the bladder.
D) where the ureters enter the true pelvis, passing by the sacroiliac joint.