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
Which of following is not derived from first pouch? 
Select and explain. 
A. Auditory tube, B. External acoustic meatus, C. Tympanic cavity, D. Mastoid antrum
B: External acoustic meatus
Answer: B: External acoustic meatus 
Explanation: Ans. is'b' i.e., External acoustic meatus Ref: Langman's Medical Embryology 12th/e p. 326,366