This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'Cailaginous pa of the external auditory canal is? \nSelect and explain. \nA. Medial 1/3, B. Lateral 1/3, C. Medial 2/3, D. Lateral 2/3', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lateral one-third (8mm) of the total external auditory canal (24mm) is cailaginous. Reference: Dhingra 6th edition', 'role': 'assistant'}]