This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pediatrics
[{'content': 'The sequence of oxygenated blood from the placenta to the fetal hea is ________ \nSelect and explain. \nA. Umbilical aery - Inferior vena cava - ductus venosus - right atrium - left atrium, B. Umbilical aery - Superior vena cava - right atrium - ductus aeriosus - left atrium, C. Umbilical vein - ductus venosus - inferior vena cava - right atrium - left atrium, D. Umbilical vein - ductus aeriosus - superior vena cava - right atrium - left atrium', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The sequence of oxygenated blood flow from the placenta to the fetal hea is Umbilical vein - ductus venosus - inferior vena - right atrium - left atrium. Ref: Nelson textbook of pediatrics 21st edition pGno: 2345', 'role': 'assistant'}]