This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'In nerve, the magnitude of the action potential overshoot is normally a function of the \nSelect and explain. \nA. Magnitude of the stimulus, B. Intracellular potassium concentration, C. Extracellular sodium concentration, D. resting membrane potential', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]