Which Feature Does Not Characterize the Thin Descending Limb of the Loop

Which feature does not characterize the thin descending limb of the loop of Henle?

A) It is very permeable to water.
B) It is not very permeable to Na⁺ and Cl^-.
C) Water moves out via osmosis along its length.
D) Fluid within it becomes more concentrated as it approaches the hairpin turn of loop of Henle.
E) It is surrounded by interstitial fluid of lower osmolarity.