This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CVS Embryology, Subject name: Anatomy
The left recurrent laryngeal nerve recurs around the 
Select and explain. 
A. Left primary bronchus, B. left subclan aery, C. Left subclan vein, D. Ductus aeriosus
D: Ductus aeriosus
Answer: D: Ductus aeriosus 
Explanation: Early in embryological development, both the right and left recurrent laryngeal nerves hook (recur) around aoic arch 6. The left aoic arch 6 persists as the ductus aeriosus(distal pa) while proximal pa of it forms pulmonary aery. 6TH phyrangeal arch derivatives:- Nerve-reccurent laryngeal nerve Aery- pulmonary aery (and ductus aeriosus) Muscles - all muscles of larynx except cricothyroid.