This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetus Placenta & Fetal Membrane, Subject name: Gynaecology & Obstetrics
Ligamentum teres is formed after: 
Select and explain. 
A. Obliteration of the umbilical vein, B. Obliteration of the ductus venous, C. Obliteration of the ductus arteriosus, D. Obliteration of the hypogastric artery
A: Obliteration of the umbilical vein
Answer: A: Obliteration of the umbilical vein 
Explanation: Ans. is a, i.e. Obliteration of the umbilical veinVesselRemnantUmbilical arteryMedial umbilical ligamentLeft umbilical veinLigamentum teres of the liver