A 58-year-old male bricklayer is admitted to the hospital with severe pain that radiates from his lower back to the pubic region. Ultrasound examination reveals that a kidney stone is partially obstructing his right ureter; the examination also indicates the presence of a second ureter on the right side. Which of the following is the most likely cause of this latter finding?
Failure of ureteric bud to form Early splitting of the ureteric bud Failure of urorectal septum to develop Persistent urachus