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: Gynaecology & Obstetrics
Ligamentum teres is formed from : 
Select and explain. 
A. Umbilical Aery, B. Umbilical Vein, C. Urachus, D. Persistent vitellointestinal duct
B: Umbilical Vein
Answer: B: Umbilical Vein 
Explanation: Umbilical Vein