Reabsorption of glucose occurs in ..... of the nephron.

Given below are two statements:
Statement $I$: In the nephron,the descending limb of the loop of Henle is impermeable to water and permeable to electrolytes.
Statement $II$: The proximal convoluted tubule is lined by simple columnar brush border epithelium and increases the surface area for reabsorption.
In the light of the above statements,choose the correct answer from the options given below:

In the distal convoluted tubule $(DCT)$ of the nephrons:

During urine formation,the tubular cells secrete substances like ........... into the filtrate.

Part of the nephron where conditional reabsorption of $H_2O$ and $Na^+$ occurs is:

Which substances are secreted in the $DCT$?