The function of the circulatory system can be affected by a variety of factors, including disease and genetic disorders. Which of the following changes to the circulatory system would
cause oxygen-rich blood to mix with oxygen-poor blood, and thus reduce oxygen distribution to all body cells?
O A Capillary walls thicken slightly in the lungs
OB. The heart rate increases due to intense exercise.
OC A hole develops between the two sides of the heart, allowing blood to flow in both directions.
OD. A defect in a heart valve causes some blood to flow from the right ventricle into the right atrium