Which force can stabilize a DNA double-helix?

• A. Hydrophobic bases are found in the interior of the helix where each base- pair is stabilized by the same number of hydrogen bonds.
• B. Hydrophilic sugar-phosphate groups are found on the exterior of the helix where they can interact with water.
• C. Non-covalent N-glycosidic bonds can form between nitrogenous bases in opposite strands in the helix.
• D. Covalent base-stacking interactions can occur between adjacent bases within the same strand in the helix.