This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fetal circulation, Subject name: Pediatrics
[{'content': 'Maximum oxygen saturation is there in which of the following blood vessels in a fetus? \nSelect and explain. \nA. Ascending aoa, B. Descending aoa, C. Inferior vena cava, D. Ductus venosus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Oxygen saturation of different blood vessels in fetus: Umbilical vein > Ductus venosus > Inferior vena cava > Ascending aoa > Descending Aoa > Umbilical aeries', 'role': 'assistant'}]