A 3 year old boy presents with fever, dysuria and gross hematuria.Physical examination shows a prominent suprapubic area which is dull on pecussion.Urinalysis reveals red blood cells but no proteinuria.Which of the following is the most likely diagnosis ?

• A. Urinary tract infection
• B. Acute glomerulonephritis
• C. Teratoma
• D. Posterior urethral valves