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: Radiology
A child with acute respiratory distress showing hyperinflation of the unilateral lung in X-ray is due to – 
Select and explain. 
A. Staphylococcal bronchopneumonia, B. Aspiration pneumonia, C. Congenital lobar emphysema, D. Foreign body aspiration
D: Foreign body aspiration
Answer: D: Foreign body aspiration 
Explanation: Sudden onset of respiratory distress with hyperinflation of lung suggest the diagnosis of foreign body aspiration.

"Foreign body aspiration should always be considered as a potential cause of stridor and airway obstruction in children".

Congenital lobar emphysema can also cause respiratory distress with hyperinflation of lung. But congenital lobar emphysema produces respiratory distress immediately after birth i.e. in neonatal periods.