Answer: C
It can't be A because there are no nucleic acids in DNA polymers
It isn't B because DNA is a polymer of nucleotides of MONOmers that are nucleic acids.
It can't be D because the 3 parts of a nucleotide is a sugar, nitrogenous bases(adenine, guanine, thymine, and cytosine), and a phosphate group.
It cannot be E because there are no proteins in nucleotides.
Answer C is the only answer that fit the sentence perfectly.