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': 'Closure of the fetal circulatory adjustments occurs functionally in the following sequence:? \nSelect and explain. \nA. Ductus venosus> Foramen ovale > Ductus aeriosus, B. Ductus aeriosus > Formen ovale > Ductus venosus, C. Ductus venosus > Ductus aeriosus > Foramen ovale, D. Ductus aretriosus > Ductus venosus > Foramen ovale', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Functional closure of the fetal circulatory adjustements occurs in the following sequence: Ductus venosus > Foramen ovale > Ductus aeriosus. Fetal circulatory adjustment Functional closure Anatomical closure Ductus Venosus After removal of the placenta 7 days Foramen ovale At bih-after breathing is initiated Months to years Ductus aeriosus 10-15 hours 10-21 days Ref: Nelson textbook of pediatrics 21st edition Pgno: 2162', 'role': 'assistant'}]