Answer: Option (c) is the correct answer.
Explanation:
Backbone in a nucleic acids strand is made up of sugar molecules attached with phosphodiester bond.
This sugar-phosphate linkage helps in joining of nucleotides in a DNA sequence. Due to this backbone structural framework of nucleotides is formed. In DNA, the sugar is deoxyribose.
Thus, we can conclude that the backbone in a nucleic acids strand is called sugar backbone.
With a pH of five, it would mean that this substance is a weak acid one would also it expect it would be sour.