An 8-year-old boy and his father visit the pediatrician's office with reports of a sudden onset of abdominal pain and reddish-brown urine. A urinalysis shows 4+ protein. On taking the boy's health history, the nurse learns that he had strep throat a little over a week ago. Assessment findings: Temp 100.6F, RR-22. HR-105, BP= 130/89 Which condition should the nurse suspect?

A. Acute glomerulonephritis is characterized by the sudden onset of hematuria (reddish-brown urine), proteinuria (4+ protein), and a recent history of streptococcal infection, making it the most likely diagnosis. B. Renal agenesis is a congenital condition and would not present suddenly with abdominal pain and hematuria. C. Nephrotic syndrome typically presents with significant proteinuria, but the acute onset of symptoms and recent strep throat history point more toward glomerulonephritis. D. Polycystic kidney disease usually presents with abdominal or flank pain, hypertension, and hematuria over a more chronic course, not typically after an acute infection.