<prompt> In the absence of vasopressin, the greatest fraction of filtered water is absorbed in theProximal tubule.Loop of Henle.Distal tubule.Cortical collecting duct.  <response>: Because the ratio of the concentration in tubular fluid to the concentration in plasma TFP of the nonreabsorbable substance inulin is 2.5 to 3.3 at the end of the proximal tubule, it follows that 6070 of the filtered solute and 6070 of the filtered water have been removed by the time the filtrate reaches this point. 