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': 'Subglottic stenosis in term infants is a subglottic diameter of less than: \nSelect and explain. \nA. 2 mm, B. 3 mm, C. 4 mm, D. 5 mm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A subglottic diameter of less than or equal to 4 mm in a full-term neonate is considered to be abnormal.', 'role': 'assistant'}]