Identifying Nitrogenous Bases in DNA

Nucleic acids, namely DNA and RNA, play critical roles in the storage and transfer of genetic information within biological systems. DNA, or deoxyribonucleic acid, is composed of two strands forming a double helix, where each strand is made up of nucleotides. Each nucleotide consists of a phosphate group, a sugar (deoxyribose in DNA), and a nitrogenous base. During DNA replication, the two strands separate, and new nucleotides are added to form two new strands. Which of the following nitrogenous bases is found in DNA?