A 17-year-old female presents with 10 days of fever, productive cough, headache, sore throat, and rhinorrhea. She also reports she has been more tired than usual, without much of an appetite. Her past medical history is unremarkable, and immunizations are up-to-date. Her temperature is 102.2ºF, heart rate is 108 beats/min, respiratory rate is 24 breaths/min, and oxygen saturation is 90% on room air. On physical examination, the patient is ill appearing, with bibasilar rales on lung auscultation. Chest x-rays show increased bronchial markings, with an interstitial infiltrate in the right lower lobe. Which of the following is the most likely cause of the patient’s condition?

(A)          Asthma exacerbation

(B)          Mycoplasma pneumonia

(C)          Laryngotracheobronchitis

(D)          Bordetella pertussis infection

(E)          Viral lower respiratory tract infection