Which of the Following Statements Best Describes Changes in the Newborn

Which of the following statements best describes changes in the newborn circulation system at birth?

A) Few substantive changes take place at birth. The circulation system is nearly complete in the eighth month of the mother's pregnancy.
B) Various fetal veins and arteries close spontaneously and eventually undergo fibrosis, thus closing off fetal shunts between arterial and venous circuits.
C) The major fetal shunts remain open for some days after birth until the newborn's lungs are fully functioning.
D) The umbilical vein and umbilical artery continue to function for some days after birth and then eventually become thrombosed.
E) None of the above is true.