What does the hormone ADH (vasopressin) do to the nephrons in the kidney?
a. ADH results in the addition of aquaporins in cells at specific regions of the nephron
b. ADH constricts the renal tubules so that less fluid is excreted
c. ADH results in dehydration of the arterial blood
d. ADH constricts the renal tubules so that more fluid is excreted