Thirteen month old Rashon has had cough and rhinorrhea for the past three days. His mother reports that several kids at his daycare have colds. She is worried about Rashon because he has noisy breathing today and feels warm. On physical exam, you find mild retractions and nasal flaring. You hear diffuse rhonchi, fine inspiratory crackles, and some wheezes. His rectal temperature is 100.2 F. Your preceptor orders a chest x-ray, which has some hyperinflation. There is no previous or family history of reactive airway disease. There has been a lot of RSV in the community. Your clinical diagnosis would most likely be A. pneumonia B. bronchiolitis C. asthma D. bronchitis E. cystic fibrosis