Answer:A) a DNA nucleotide
Explanation: DNA and RNA are nucleic acids. Nucleic acids are made up of monomeric units called nucleotides. Nucleotides are made up of a nitrogenous base, a pentose sugar and a phosphate group. In DNA, the bases found are Adenine, Thymine, Cytosine and Guanine and the pentose sugar found in DNA is deoxyribose, but in RNA the bases found are Adenine, Uracil, Cytosine and Guanine; the pentose sugar found in RNA is ribose.