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: Dental
[{'content': 'The pharyngeal structure established in early age and remain constant throughout life is? \nSelect and explain. \nA. Depth of oropharynx, B. Depth of nasopharynx, C. Width of nasopharynx, D. Width of oropharynx', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Multiple recent researches have concluded that the depth of nasopharynx is established during the first 2 years of life and these dimensions remains constant thereafter.\nRef: Graber LW, Vanarsdall RL, Vig KW, Huang GJ. Orthodontics: current principles and techniques.', 'role': 'assistant'}]