A 1-year-old girl has bee...

A 1-year-old girl has been experiencing fever, cough, and shortness of breath for the past 5 days, with persistent fever throughout the day. The cough and shortness of breath worsen at night. Her father is an active smoker. Vital signs revealed an increased heart rate of 160 beats per minute, an elevated respiratory rate of 33 breaths per minute, a temperature of 38°C, and a decreased oxygen saturation level of 94%. On physical examination, bilateral chest retractions and dry crackles at the base of the lungs were observed. Laboratory results showed an elevated white blood cell count of 18,000 cells/cumm. The patient was diagnosed with infant pneumonia and was treated with nasal cannula oxygen as supportive therapy, with planned initiation of antibiotics as empiric therapy. What is the appropriate antibiotic choice to treat this patient?