The Nurse Notes That the Results of an Intravenous Pyelogram

The nurse notes that the results of an intravenous pyelogram indicate a left hydroureter and hydronephrosis in a female patient who was hospitalized with a markedly distended bladder.A catheterization for residual urine obtained 1650 mL.What does the nurse understand about these findings that are characteristic of a urinary tract obstruction?

A) They are located at the bladder neck.
B) They are caused by ureteral calculi.
C) They are situated at the ureteropelvic junction.
D) They are caused by a ureteral stricture.