Topic : function of the tubules

Complete the analogy for the following Reabsorption of 70-80% of electrolytes : PCT :: Conditional reabsorption of Na$^+$ :

The osmolarity of the glomerular filtrate in a___ is less than 300 mOsmol/L. Choose the option that correctly fills the blank a.

Even in presence of ADH, the maximum reabsorption of water occurs in

Choose the incorrect statement w.r.t. function of the renal tubule.