<prompt> Which differentiating prerenal azotemia with ATN features favouring pre-renalUrine osmolality 500 mosmolkgSodium spot excretion 10 mlLPlasma transferrinIg rationone  <response>: The normal 24-hour urine osmolality is, on average, 500-800 mOsmolkg of water.After 12-14 hours of fluid intake restriction, the urine osmolality should exceed 850 mOsmolkg of water 