Answer : 1. "phosphates and sugars"
Explanation :

Answer: A) phosphates and sugars Explanation: In DNA, adjacent nucleotides are linked by a phosphodiester bond: a covalent bond is formed between the 5' phosphate group of one nucleotide and the 3'-OH group of another.   Hence, in this manner, each strand of DNA has a "backbone" of phosphate-sugar-phosphate-sugar-phosphate.