The Transport System That Maintains the Sodium Gradient Across the Cell

The transport system that maintains the sodium gradient across the cell membrane:

A) involves an ATPase enzyme.
B) is a symport system with glucose as a cotransported solute.
C) moves sodium into the cell.
D) hydrolyzes ATP in the membrane, in a mechanism independent of the movement of sodium ion.
E) is an antiport system that derives its energy from high concentrations of glucose.