At the bottom of the loop of Henle,the glomerular filtrate is . . . . . . .

Select the correct option:
$(1)$ The counter-current mechanism is maintained by the Loop of Henle and the vasa recta.
$(2)$ The ascending limb of the Loop of Henle is impermeable to water.

Given below are two statements with respect to counter current mechanism.
$Statement-I$: Tissue fluid around the descending limb of Henle's loop becomes concentrated, during the counter current mechanism.
$Statement-II$: Water moves out from the descending limb of Henle's loop into the tissue fluid by osmosis.
In the light of the above statements, select the correct option from the codes given below:

The osmotic concentration in the interstitial fluid is primarily due to the presence of $.....$.

Human urine is usually . . . . . . compared to human blood.

Urine is concentrated in which part of the nephron?