A 4-year-old girl presents with fever, vomiting and abdominal pain. She is irritable and refuses to pass urine. Dipstick shows leukocytes and nitrites. What is the most appropriate investigation or management step?ANo further investigation; treat symptomaticallyBSend urine for culture and start antibiotics promptlyCDelay antibiotics until culture confirms infectionDReassure and review in 1 week without antibioticsEStart long-term prophylactic antibiotics without treatment courseCheck my answer