I’m really trying to do it but I still don’t understand it

answer; the correct answer is (beta)

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.