Choose the incorrect sentence$(s)$.
$(I)$ Malpighian corpuscles,$PCT$ and $DCT$ of the nephron are situated in the medulla of the kidney.
$(II)$ The loop of Henle dips into the medulla.
$(III)$ In juxtamedullary nephrons,the loop of Henle is too short and extends very little into the medulla.
$(IV)$ Vasa recta is absent or highly reduced in cortical nephrons.

• A
  $I, II$
• B
  $II, IV$
• C
  $I, III$
• D
  $III, IV$