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: Medicine
Widened anion gap is caused by all EXCEPT : 
Select and explain. 
A. Lactic acidosis, B. Diarrhea, C. Diabetic keto-acidosis, D. Methanol poisoning
B: Diarrhea
Answer: B: Diarrhea 
Explanation: Ans.(b) Diarrhea* Anion gap :The anion gap is the difference between primary measured cations (sodium Na+ and potassium K+) and the primary measured anions (chloride Cl and bicarbonate HCO3) in serum.* So we take value of sodium and from it subtract the value of chloride and bicarbonate.* Value of Normal anion gap =10 to 12 mmol/LAG calculated as follows: AG = Na+ - (Cl" + HCO3~)Normal anion gap(Mn: FUSED CAR)Increased anion gap(Mn: MUDPILES)Decreased anion gap(Mn: BPH-M)F- Fistula pancreaticM - MethanolBromide intoxicationU- UreterosigmoidostomyU - UremiaPlasma cell dyscrasiaS- Small bowel fistulaD - DKA/ AKA/ SKA (diabetic/alcoholic/ starvation)HypoalbuminemiaE- Extra chlorideP - Paraldehyde / phenforminMonoclonal proteinD- Diarrhea1 - Iron / INH C- Carbonic anhydraseInhibitor (acetazolamide)L - Lactic acidosis A- Adrenal insufficiencyR- Renal tubular acidosisE - Ethylene glycol S - Salicylates