A 15-year-old high school wrestler has been taking diuretics to lose weight to compete in a lower weight class. Which of the following medical tests is most likely to be given?

Diuretics can disrupt the sodium and potassium balance, potentially leading to cardiac complications. Monitoring the lab values of potassium and sodium is crucial to assess electrolyte imbalances due to diuretic use. Testing glucose and hemoglobin levels is not directly related to diuretic use in this context. An ECG would be indicated if there were signs or symptoms of cardiac abnormalities, but it is not the primary test to monitor the effects of diuretics. A CT scan is not typically used to assess electrolyte imbalances caused by diuretics.