A 9 month old infant presents with a 2- day history of fever, cough and breathlessness following an upper respiratory infection. She is febrile and has a respiratory rate of 80/min. Intercostal and subcostal retractions and extensive rhonchi on auscultation. A chest X-ray reveals a hyperinflated chest -
Bronchial asthma
Foreign body aspiration
Bacterial pneumonia
Bronchiolitis
Ans. is 'd' i.e., Bronchiolitis