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
[{'content': 'The following X-ray depicts \nSelect and explain. \nA. Acute Laryngotracheobronchitis, B. Acute Epiglottitis, C. Foreign body aspiration, D. Retropharyngeal abscess', 'role': 'user'}, {'content': 'Answer: B \nExplanation: X-ray shows Thumb sign which is diagnostic of acute Epiglottitis', 'role': 'assistant'}]