Which of the following are actions of ADH on the kidneys?
a) Insertion of aquaporins into the principal cells
b) Decreasing urea permeability in the inner medullary collecting ducts
c) Increasing the activity of the Na⁺-K⁺-2Cl⁻ cotransporter of the thick ascending limb
d) Increasing the activity of the Na⁺-Cl⁻ cotransporter of the early distal tubule