<prompt> Decreased fractional excreion of sodium is caused by-Prerenal azotemiaCortical ischemiaGlomerulonephritisRenal tubular acidosis  <response>: Ans. is a i.e., Prerenal azotemia Diagnostic IndexPrerenal ARFIntrinsic Renal ARFo Fractional Excretion of NaQ11o trine Sodium ConcentrationQ mmolL1020o Urine Creatinine to PlasmaQ Creatinine ratio4020o trine osmolalityQ mosmolkgH2O500-350o Renal failure IndexQ11o Urine urea NitrogenQ to plasma urea Nitrogen83o Plasma BUNCreatinineQ Ratio2010-15o Urinary SedimentQHyaline CastsMuddy Brown Granular Casto Urine Specific gravityQ1.0201.010 