Final answer:
The sodium-potassium pump in neurons primarily controls the Resting Membrane Potential by moving ions against their concentration gradients using ATP, thereby maintaining the necessary electrical gradient critical for nerve impulse transmission.
Step-by-step explanation:
The primary control of Resting Membrane Potential (RMP) is the sodium-potassium pump in neurons. This active transport mechanism moves sodium ions out of cells and potassium ions into cells against their concentration gradients, utilizing energy from ATP. The sodium-potassium pump brings two K+ ions into the neuron while expelling three Na+ ions for every molecule of ATP consumed, thus helping to maintain the difference in charge across the cell membrane. This difference in charge is critical for the transmission of nerve impulses, acting as a buffer in the neuron's interior compared to the exterior. Therefore, the correct answer to the question is 'b. Sodium-Potassium Pump - Neurons'.