Which of the following is not TRUE of K⁺ leak channels?

A) are always open.
B) are 50 - 100 times more prevalent than Na⁺ leak channels.
C) have the greatest contribution to the resting potential of the cell.
D) are responsible for the depolarization phase of the action potential.
E) allow K⁺ ions to "leak" down their concentration gradient and out of the cell.