A 2-year-old child presents to the hospital with a fever of 38.4 Celsius and the parents state the child has had dysuria and Irritability, with a loss of appetite. What diagnostic test should the nurse expect to be ordered first based on the symptoms?

A complete blood count (CBC) may be ordered later if further infection or sepsis is suspected, but it is not the first diagnostic test. B. Urinalysis is the most appropriate initial test to diagnose a urinary tract infection (UTI), which is common in children with symptoms such as dysuria and irritability. C. An abdominal ultrasound is more appropriate if there are concerns about abdominal pathology, which is not suggested by the symptoms. D. A bladder scan is not the first diagnostic step and would be used to assess post-void residual urine if necessary.