Ans. C. 15 to 20 L/dayUrine flow rate in the absence of antidiuretic hormone (ADH) can approach approximately 10% to 13% of the glomerular filtration therefore, for a glomerular filtration of 155 L/day, urine flow could be as much as 15 to 20 L/ day. To maintain this level of urine flow, the individual must consume an equivalent amount of water per day.