34. Which of the following statements about mammalian nephron is correct? (A)Reabsorption of water relies on active transport of water. (B) The ascending limb of the loop of Henle is impermeable to water. (C)Osmolarity in the kidney cortex is higher than that in the medulla. (D) Salt reabsorption takes place in the descending limb of the loop of Henle.