The Greatest Difference in the Concentration of Respiratory Gases Is

Multiple Choice

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?

A) the pulmonary vein and the jugular vein
B) the veins from the right and left legs
C) the pulmonary artery and the inferior vena cava
D) the pulmonary vein and the aorta
E) the inferior vena cava and the superior vena cava