A previously healthy 4-year-old boy is brought to the emergency department after a 1-day history of increased respiratory distress, fatigue, and decreased oral intake. He has a barking cough and is febrile. On examination, he has inspiratory stridor, suprasternal retractions, and decreased breath sounds bilaterally. Which of the following is the most likely diagnosis?
a) Epiglottitis
b) Croup
c) Foreign body aspiration
d) Bacterial tracheitis