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: Anatomy
the reason for the long left recurrent laryngeal Nerve is due to the persistence of which arch aery? 
Select and explain. 
A. 3rd Arch, B. 5th Arch, C. 4th Arch, D. 2nd Arch
C: 4th Arch
Answer: C: 4th Arch 
Explanation: Left RLN wind round the arch of aosta Arch of Aosta derived from left 4th Arch aery ref : VISHRAM SIGN EMBRYOLOGY