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': 'A recognised cause of stridor in newborn – \nSelect and explain. \nA. Cystic hygroma, B. A Vascular ring, C. Laryngomalacia, D. All are true', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Stridor\n\nStridor refers to the physical finding of excessively noisy breathing and is generally due to airway obstruction.\n\nCauses of Stridor in a child.\nInfections\n\nCroup (laryngotracheobronchitis)\nEpiglottitis\nBacterial tracheitis\nRetropharyngeal abscess\n\nCongenital\n\nLaryngomalacia\nVocal cord palsy\nSubglottic stenosis\nVascular ring\nSaccular cyst\n\nNeoplasms\n\nSubglottic hemangioma\nLaryngeal papillomas\nCystic hygroma, when it occurs in larynx then it can cause respiratory tract obstruction - Nelson 18th/ep. 1773', 'role': 'assistant'}]