Which of the following forces can stabilize a normal DNA double-helix

A) Base-stacking is a non-covalent interaction that occurs between the relatively hydrophobic bases in the interior of the helix. B) Base-pairing is a non-covalent interaction that occurs between adjacent bases in the same strand of the DNA molecule. C) The hydrophilic sugar-phosphate groups are on the exterior of the helix where they can interact with each other. D) The deoxyribose rings form N-glycosidic bonds with the phosphate groups that link neighboring nucleotides.