This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of Larynx, Subject name: ENT
[{'content': "Narrowest part in infant's respiratory tract is: \nSelect and explain. \nA. Subglottis, B. Glottis, C. Carina, D. None of these", 'role': 'user'}, {'content': "Answer: A \nExplanation: (a) Subglottis(Ref. Scott Brown, 8th ed., Voll; 326)In infant's larynx the diameter of cricoid cartilage is smaller than the glottis, making subglottis the narrowest part, whereas in adults the narrowest part is the glottis.", 'role': 'assistant'}]