In the mammalian kidney,the loop of Henle is present in:

What is the wall of Bowman's capsule in the nephron made of?

Arrange the following parts of the nephron in a sequential manner and select the correct option accordingly.
$I.$ Glomerulus
$II.$ Bowman's capsule
$III.$ Henle's loop
$IV.$ Proximal convoluted tubule $(PCT)$
$V.$ Collecting duct
$VI.$ Distal convoluted tubule $(DCT)$

Kidneys are reddish-brown,bean-shaped structures situated between the levels of . . . . . . thoracic and . . . . . . lumbar vertebrae.

The figure shows the human urinary system with structures labelled $A$ to $D$. Select the option which correctly identifies them and gives their characteristics and/or functions.

Which of the following blood vessels contains the minimum concentration of urea in the blood?