A preterm infant is now 7 weeks old. She was intubated for 2 weeks and was weaned off oxygen at 3 weeks of age. You are about to leave your office for the Thanksgiving holiday when the emergency room calls to tell you she has recent onset of hypoxia, respiratory distress, wheezes, and runny nose. A chest radiograph reveals patchy infiltrates and hyper-expansion in both lung fields. The newborn's 2-year-old sibling has an upper respiratory infection. For the mentioned clinical scenario, select the most likely diagnosis