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': 'True statements about ions composition in body \nSelect and explain. \nA. Intracellular & Extracellular ions compositions are same, B. Phosphorus and Mg++ are major ions intracellularly, C. Na+, Cl- principal ions in E.C.F., D. Kidney tightly regulates Na+, K+, Cl- composition', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Electrolyte constitutes about 7% of total body weight. In ECF Na, Cl is the principle ions.Whereas K is more intracellularly. (REF TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO 62,22)', 'role': 'assistant'}]