This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
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 - 
Select and explain. 
A. Bronchial asthma, B. Foreign body aspiration, C. Bacterial pneumonia, D. Bronchiolitis
D: Bronchiolitis
Answer: D: Bronchiolitis 
Explanation: Ans. is 'd' i.e., Bronchiolitis