The most common cause of renal scarring in a 3 years old child is:
c. Vesicoureteral reflux induced pyelonephritis(Ref: Nelson's 20/e p 2562-2567Ghai 8/e p 485-486)Most common cause of renal scarring in a child is VUR-induced pyelonephritis.
Trauma
Tuberculosis
Vesicoureteral reflux induced pyelonephritis
Interstitial nephritis
Kidney