<prompt> The most common congenital anomaly of the urinary tract:EpispadiasHypospadiasExstrophy of bladderPosterior urethral valve  <response>: b. HypospadiasRef: Nelson 20e p 2573-2578Hypospadias is a urethral opening on the ventral surface of the penile shaft affecting 1 in 250 male newborns.Exstrophy of urinary bladder:It occurs in 1 in 35,000-40,000 births; Male: female ratio is 2:1Severity ranges from simple epispadias in boys to cloacal exstrophy. Posterior urethral valve:The most common cause of severe obstructive uropathy in children is posterior urethral valves, affecting 1 in 8,000 boys. 