An intravenous pyelogram is performed on a patient to evaluate the function and structure of her kidneys. Examination of the resulting radiographs reveals that the left kidney is normal but that there is a duplication of the ureter and renal pelvis on the right side. Further testing reveals that kidney function is normal. This variation is a result of abnormal development of which of the following structures?

1. A)Mesonephric tubules
2. B)Metanephric blastema
3. C)Allantoic duct
4. D)Ureteric budGABARITO
5. E)Mesonephric duct