Question

what makes up the backbone of dna?
○ sugar and phosphates
○ a polymer of nitrogenous bases
○ nitrogenous bases, sugar, and phosphates
○ nitrogenous bases and sugar

Explanation:

The backbone of DNA is composed of alternating sugar (deoxyribose) and phosphate groups. Nitrogen - ous bases are attached to the sugar but are not part of the backbone structure.

Answer:

sugar and phosphates