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: Anatomy
A double aoic arch is due to persistent: 
Select and explain. 
A. Right 4th arch, B. Right 6th arch, C. Left 4th arch, D. Left 6th arch
A: Right 4th arch
Answer: A: Right 4th arch 
Explanation: Right 4th arch