Which of the following statements about the reabsorption process in Henle's loop are correct?
$(a)$ The descending limb of Henle's loop is permeable to water but almost impermeable to electrolytes.
$(b)$ Urine gets concentrated in Henle's loop.
$(c)$ Reabsorption of $Na^+$ and water takes place in Henle's loop.
$(d)$ Active or passive transport of electrolytes occurs in the ascending limb of Henle's loop.
Choose the correct answer from the options given below:

• A
  $(a)$ and $(b)$ only
• B
  $(a)$, $(c)$ and $(d)$ only
• C
  $(a)$, $(b)$ and $(c)$ only
• D
  $(a)$, $(b)$ and $(d)$ only