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: ENT
[{'content': 'Most common cause of stridor in infants is: \nSelect and explain. \nA. Laryngomalacia, B. Laryngeal cysts, C. Vocal cord polyp, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Laryngomalacia is the most common cause of stridor in infants and is also the most common congenital laryngeal abnormality, accounting for approximately 60% of cases.', 'role': 'assistant'}]