Which of the following statements is true of primary grade IV-V vesicoureteric reflux in young children ?

• A. Postnatal scarring may occur even in the absence of urinary tract infections
• B. Renal scarring usually begins in the midpolar regions
• C. Oral amoxicillin is the choice antibiotic for prophylaxis
• D. Long-term outcome is comparable in patients treated with either antibiotic prophylaxis or surgery