<prompt> A child with acute respiratory distress shows hyperinflation of unilateral lung in chest X-ray. Most likely cause for above presentation is:Staphylococcal bronchopneumoniaAspiration pneumoniaCongenital lobar emphysemaForeign body aspiration  <response>: Foreign body aspiration is the commonest cause of acute lung collapse in a child. Ref: Chest Radiology: The Essentials By Jannette Collins, Eric J. Stern, 2007, Page 196 