A previously well 1-year-old infant has had a runny nose and has been sneezing and coughing for 2 days. Two other members of the family had similar symptoms. Four hours ago, his cough became much worse. On physical examination, he is in moderate respiratory distress with nasal flaring, hyperexpansion of the chest, and easily audible wheezing without rales. His chest radiographs are shown. Which of the following is the appropriate next course of action?
a) Initiate antibiotics
b) Administer bronchodilators
c) Administer corticosteroids
d) Administer intravenous (IV) fluids