Dear student
Selective Reabsorption is the process of reuptake of certain molecules like ions from the filterate as they through nephron. It occurs in proximal and distal convulated tubules which extend downs the Bowman's capsule.
Factors responsible for amount of water reabsorption along the tubular part of nephron :-
1. The amount of excess water present in the body.
2. The amount of waste to be excreated out of the body.
Regards