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': 'Common causes of congenital stridor in child - \nSelect and explain. \nA. Laryngeal web, B. Laryngomalacia, C. Haemangioma, D. Subglottic stenosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: STRIDOR\n\nDue to upper airway obstruction,\n\nTypes -\n\nInspiratory stridor - Obstruction above vocal cords (supraglottic).\nExpiratory stridor - Obstriction distal trachea.\nBiphasic - From supragiottic or proximal tracheal.\n\nCauses \xa0Infective:\n\nCroup (lanyngo tracheo bronchitis)\nBacterial trachetis\nRetropharyngeal abscess\n\nCongenital:\n\nLaryngomalacia: 60% of all total most common cause.\nVocal cord paralysis - 2nd most common.\nSubglottic stenosis - 3rd most common. \xa0\n\nIatrogenic :\n\nLong-term intubation leads to subglottic stenosis - the most common causes of Acquired stridor in children.\nNeoplasm: Recurrent respiratory papilloma (RRP) MC a benign tumour and larynx.', 'role': 'assistant'}]