This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid & Electrolyte, Subject name: Pediatrics
[{'content': 'The normal value of anion gap is: \nSelect and explain. \nA. 8-16 mEq/l, B. 20-25 meq/l, C. 50 meq/l, D. 75 meq/l', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. 8-16meq/lTo achieve electrochemical balance, the number of negatively charged anions should equal the positively charged ions (cations)Na++K++ Unmeasured Cations (UC)=(Cl-+HCO3- + Unmeasured anions (UA)RearrangingNa++K+-(Cl-+HCO3- )=UA-UC= Anion Gap (AG)Because normally the total unmeasured anions exceed the unmeasured cations; there is a anion gap.', 'role': 'assistant'}]