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: Biochemistry
[{'content': 'Normal anion gap is mostly due to  : \nSelect and explain. \nA. Unmeasured Na+ ion, B. Unmeasured Cl- ion, C. Unmeasured proteins, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Normal anion gap is due to Unmeasured proteins. Normally in the plasma, the concentration of anion and cations\xa0are equal to maintain electrical neutrality. Thus, no real anion gap exists in the plasma and this is purely a diagnostic concept.\xa0\nGuyton and Hall Textbook of medical physiology Pg-426', 'role': 'assistant'}]