Glucose Transport Across Cell Membranes Varies Depending Upon Blood Glucose

Glucose transport across cell membranes varies depending upon blood glucose levels. When glucose levels are high, glucose transport exhibits saturation kinetics. When glucose concentrations are low, the transport of glucose across the membrane is dependent upon the sodium ion concentration. What types of transport is observed for glucose?

A) facilitated diffusion at high [glucose], secondary active transport at low [glucose]
B) simple diffusion at high [glucose], secondary active transport at low [glucose]
C) facilitated diffusion at high [glucose], primary active transport at low [glucose]
D) simple diffusion at high [glucose], primary active transport at low [glucose]
E) none of the above are correct