<prompt> A 65-year-old man has urine output of 10 mLh following abdominal aoic aneurysmectomy. Acute tubular necrosis is suggested by the presence of which of the following?Urine osmolality of more than 500 mOsmkgUrine sodium of more than 40 mEqLFractional excretion of sodium of 1Blood urea nitrogen BUN-to-serum creatinine ratio SCR of more than 20  <response>: Oliguria-Acute tubular necrosis -Intrinsic Renal Failures Prerenal Failures Intrinsic Renal Failures Urine osmolality mOsmkg 500 350 Urine sodium mEqL 20 40 Fractional excretion of sodium 1 2 BUNSCR 20 10 UrinePCR 40 20 