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': 'Which of following is not derived from first pouch? \nSelect and explain. \nA. Auditory tube, B. External acoustic meatus, C. Tympanic cavity, D. Mastoid antrum', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is'b' i.e., External acoustic meatus Ref: Langman's Medical Embryology 12th/e p. 326,366", 'role': 'assistant'}]