This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concepts in physiology, Subject name: Physiology
[{'content': 'Resting membrane potential is mainly due to: \nSelect and explain. \nA. Na+, B. K+, C. Cl-, D. Ca++', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Nernst equilibrium potential for K+ =-94 mV is much close to RMP value of -90mV in nerves Nernst equilibrium potential for Na+= +61mv Hence RMP is close to or mainly due to K+ ion.', 'role': 'assistant'}]