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
Ligamentus aeriosus is a remnant of - 
Select and explain. 
A. Ductus aeriosus, B. Ductus caroticus, C. Ductus venosus, D. None
A: Ductus aeriosus
Answer: A: Ductus aeriosus 
Explanation: A i.e. Ductus aeriosus