Originally Posted by MPHer83
I am thinking it's d. as the contercurrent mechanism for concentrating urine depends on the thick ascending loop of henle and the resorption of Na, K, and Cl into the medulla. If you have another answer please share. I might be wrong.
answer should be DIAMETER OF DIS TUBULE
because more the diameter of dis tubule more surface area will be avilable for water absorption........and final urin concentration occures in distal tubule by action of ADH....I have also seen this question somewhere but don't remember where? correct me if i m wrong