The umbilical artery carries blood from the fetus to the placenta and the umbilical vein carries blood from the placenta to the fetus. How does the composition of the blood in the umbilical artery and the umbilical vein differ?
A. Blood in the umbilical artery contains less glucose than blood in the umbilical vein.
B. Blood in the umbilical artery contains less carbon dioxide than blood in the umbilical vein.
C. Blood in the umbilical vein contains less oxygen than blood in the umbilical artery.
D. Blood in the umbilical vein contains more urea than blood in the umbilical artery.