This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of the Respiratory Tract, Subject name: Pediatrics
[{'content': 'Common cause of congenital stridor in child- \nSelect and explain. \nA. Laiyngomalacia, B. Laryngeal web, C. Hemangioma, D. Subglottic stenosis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Laryngomalacia STRIDORo Due to upper airway obstruction, o Types -Inspiratory stridor - Obstruction above vocal cords (supraglottic).Expiratory stridor - Obstriction distal trachea.Diphasic - From supraglottic or proximal tracheal.Causeso Infective:Croup (lanyngo tracheo bronchitis)Bacterial trachetisRetropharyngeal abscess o Congenital:Laryngumalacia: 60% of all total most common cause.Vocal cord paralysis - 2nd most common.Subglottic stenosis - 3rd most common.o Iatrogenic : Long term intubation leads to subglottic stenosis - most common causes of aquired stridor in children,o Neoplasm : Recurrent respiratory papilloma (RRP) MC benign tumor and laynx.", 'role': 'assistant'}]