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': 'Superior margin of infants larynx as at the level of \nSelect and explain. \nA. Cervical spine C1, B. Cervical spine C2, C. Cervical spine C4, D. Cervical spine C6', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]