This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
[{'content': 'Equilibrium potential of K+ \nSelect and explain. \nA. -70mV, B. -90mV, C. +70mV, D. +90mV', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Equilibrium potential of K+ is -90mV.(Ref: Textbook of physiology AK JAIN 4th edition page no.34)', 'role': 'assistant'}]