The nurse administers an antibiotic to a client with a respiratory tract infection. To evaluate the medication's effectiveness, what laboratory value(s) should the nurse monitor? Select all that apply.

A. Urinalysis: While urinalysis can provide information about urinary tract infections, it is not directly related to monitoring the effectiveness of antibiotic treatment for a respiratory tract infection. B. White blood cell (WBC count: Monitoring WBC count can help assess the body's response to infection. A decrease in WBC count can indicate improvement in the infection. C. Sputum culture and sensitivity: Monitoring sputum culture and sensitivity helps determine if the antibiotic is targeting the specific pathogen causing the respiratory tract infection and if the chosen antibiotic is effective against it. D. Serum potassium: Monitoring serum potassium levels is important with certain antibiotics, but it is not directly related to evaluating the effectiveness of antibiotic treatment for a respiratory tract infection. E. Red blood cell (RBC count: RBC count is not typically monitored to evaluate the effectiveness of antibiotic treatment for a respiratory tract infection. F. Blood urea nitrogen (BUN): BUN levels are not directly related to assessing the effectiveness of antibiotic treatment for a respiratory tract infection.