Which of the Following Is True for the Sodium-Potassium Exchange

Multiple Choice

Which of the following is true for the sodium-potassium exchange pump?

A) It pumps an equal number of ions into and out of the cell.
B) It passively distributes ions along their concentration gradient.
C) It passively distributes ions along their electrical gradient.
D) It pumps two potassium ions into the cell and three sodium ions out of the cell.
E) It is unrelated to maintaining ion balance in the cell.