This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction to Central Nervous System, Subject name: Physiology
Which ion has the lowest electrochemical driving force in a typical neuron with a resting membrane potential of -65 millivolts? 
Select and explain. 
A. Chloride, B. Potassium, C. Sodium, D. Calcium
A: Chloride
Answer: A: Chloride 
Explanation: The equilibrium potential for chloride averages about -70 millivolts in a typical neuron, so with a resting membrane potential of 65 millivolts, the electrochemical driving force for chloride is 5 millivolts. In case of neuron, equilibrium potential for: Potassium: -90 mV Sodium: +60 mV Calcium: +129 mV