The correct answer to this question is guanine and adenine. The hydrolysis of nucleotides produces two types of nitrogenous bases; purine and pyrimidine. While adenine and guanine are nitrogenous bases that are of the purine type, uracil or 2,4-dioxoypyrimidine, thymine or 5-methyl-2,4-dioxipyrimidine, and cytosine or 2-oxo-4-aminopyrimidine are nitrogenous bases that are of the pyrimidine type.
The easiest way to differentiate between purines and pyrimidines is that both consist of different numbers of rings. For instance, pyrimidines only have a single ring, while purines have two rings. Unlike in purines where adenine and guanine exist in both RNA and DNA, only one of the three main types of pyrimidines exists in both RNA and DNA.
That means cytosine is the only type of pyrimidine that is present in both DNA and RNA. The structures of purines consist of four nitrogen rings, while the structure of pyrimidines only consists of two nitrogen rings.