This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver, Subject name: Anatomy
[{'content': 'A pediatric surgeon is resecting a possible malignant mass from the liver of a neonate with cerebral palsy. The surgeon divides the round ligament of the liver during surgery. A fibrous remnant of which of the following fetal vessels is severed? \nSelect and explain. \nA. Ductus venosus, B. Ductus aeriosus, C. Left umbilical vein, D. Right umbilical vein', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The left umbilical vein becomes the round ligament of the liver after bih. The right umbilical vein did not leave a fibrous remnant because it was degenerated during the early embryonic period. The ductus venosus forms the ligamentum venosum; the ductus aeriosus forms the ligamentum aeriosum; Umbilical aery forms the medial umbilical ligament.', 'role': 'assistant'}]