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': 'Predominant extracellular ions area) Na+b) K+c) Cl-d) HCO3-e) PO4- \nSelect and explain. \nA. abc, B. ad, C. bc, D. acd', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Predominant Ions\nECF- Na+, Cl-, HCO3-, Ca+2\n\xa0\nICF- K+, Mg+2, protein,\xa0\xa0PO4-', 'role': 'assistant'}]