This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharyngeal Arches, Subject name: Anatomy
Double aoic arch occurs due to? 
Select and explain. 
A. Non development of right 4th aoic arch, B. Non development of left 4th aoic arch, C. Non divison of truncus aeriosus, D. Persistent distal poion of right dorsal aoa
D: Persistent distal poion of right dorsal aoa
Answer: D: Persistent distal poion of right dorsal aoa 
Explanation: Double aoic arch occurs due to persistent distal poion of right dorsal aoa. This will lead to difficulty in breathing and swallowing due to compression of bronchi and esophagus by Right side aoic arch.