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': 'Inward flow of Na+ in hea leads to \nSelect and explain. \nA. Plateu phase, B. Action potential, C. Repolarization, D. No change', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Entry of Na ions into cardiac cell leads to depolarisation. (REF TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO 52)', 'role': 'assistant'}]