question: Q:A 72-year-old man is admitted to the hospital with productive cough and fever. A chest radiograph is obtained and shows lobar consolidation. The patient is diagnosed with pneumonia. He has a history of penicillin allergy. The attending physician orders IV levofloxacin as empiric therapy. On morning rounds the next day, the team discovers that the patient was administered ceftriaxone instead of levofloxacin. The patient has already received a full dose of ceftriaxone and had no signs of allergic reaction, and his pneumonia appears to be improving clinically. What is the most appropriate next step?? 
  {'A': 'Continue with ceftriaxone as empiric therapy', 'B': 'Continue with ceftriaxone and add azithromycin as inpatient empiric pneumonia therapy', 'C': 'Switch the patient to oral azithromycin in preparation for discharge and home therapy', 'D': 'Administer diphenhydramine as prophylaxis against allergic reaction', 'E': 'Switch the patient back to levofloxacin and discuss the error with the patient'},