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': 'Narrowest pa of respiratory tract in adult is: \nSelect and explain. \nA. Trachea, B. Glottis, C. Supraglottis, D. Subglottis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The narrowest pa of larynx In adults - Glottis In children - Subglottis', 'role': 'assistant'}]