Answer:
Potassium
Step-by-step explanation:
Resting membrane potential may be defines as the voltage or charge difference between inside and outside of the cell when the cell is at rest. The resting membrane potential of the cell is -70mV.
Potassium ion channels are leaky channels that are always open and can move into and out of the cell. The potassium ions are responsible for setting of the resting membrane potential of the cell. Inward movement of sodium ions may disrupt the resting membrane potential of the cell.
Thus, the correct answer is option (B).