This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Physiology
Resting membrane potential of nerve fibre is close to isoelectric potential of: 
Select and explain. 
A. Potassium ions, B. Sodium ions, C. Chloride ions, D. Magnesium ions
A: Potassium ions
Answer: A: Potassium ions 
Explanation: RMP of nerve = -70mVEp of sodium = + 60mVEP of potassium = - 90mV Ep of chloride = -70mV (Same as RMP not closest )