This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory infections, Subject name: Pediatrics
[{'content': 'The following sign on X ray neck is seen in which of the following diseases? \nSelect and explain. \nA. Acute epiglottitis, B. Laryngotracheobronchitis, C. Laryngomalacia, D. Acute Bronchiolitis', 'role': 'user'}, {'content': "Answer: B \nExplanation: The given x ray shows 'Steeple sign' due to subglottic narrowing which is characteristically seen in Acute Laryngotracheobronchitis (Croup). Acute epiglottitis- thumb sign on lateral X-ray neck.", 'role': 'assistant'}]