This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Excitation and Action Potiential, Subject name: Physiology
[{'content': 'Point at which the ratio of K+ permeability to Na+ permeability (PK/PNa) is the greatest. \nSelect and explain. \nA. A, B. C, C. E, D. F', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Point A: RMP ( memebrane potential is closest to the equilibrium potential of potassium ion) Point B: Threshold potential Point C: Due to Hodgkin cycle rapid Na+ influx from voltage gated channels Point D: Na+ permeability maximum Membrane potential is closest to Na+ equilibrium potential Ratio of (P Na+/ P K +) maximum Point E: Potassium permeability maximum Point F: Only K+ permeability, no Na+ permeability Ratio of ( P K + / P Na+) is maximum', 'role': 'assistant'}]