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
[{'content': 'Oxygenated blood from the placenta reaches the fetal heart in utero via: \nSelect and explain. \nA. Umbilical arteries, B. Umbilical vein, C. Ductus venosus, D. Ductus arteriosus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]