This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: ENT
External auditory canal is formed by: 
Select and explain. 
A. 1st branchial groove, B. 1st visceral pouch, C. 2nd branchial groove, D. 2nd visceral pouch
A: 1st branchial groove
Answer: A: 1st branchial groove 
Explanation: 1st branchial groove Ref : HAZARIKA 3RD ED.