Problem: In December, a 4-month-old infant is brought to office for a runny nose, low grade fever, cough and audible wheezing. The child is attending daycare and other children have similar symptoms. On physical exam, the child has wheezing and intercostal retractions. The MOST likely diagnosis is: Group of answer choices A. asthma. B. respiratory syncytial virus (RSV). C. pneumonia. D. bronchitis.