What are nucleotides primarily made of?

Nucleotides are the fundamental building blocks of nucleic acids, such as DNA and RNA. They consist of three main components: a five-carbon sugar (ribose in RNA and deoxyribose in DNA), one or more phosphate groups, and a nitrogenous base. The sugar component provides the backbone of the nucleic acid structure, while the phosphate groups are involved in linking nucleotides together through phosphodiester bonds, forming the sugar-phosphate backbone. The nitrogenous base is critical for encoding genetic information and can vary among nucleotides, allowing for the diversity of genetic codes. This combination of sugar, phosphate, and nitrogenous base is what characterizes nucleotides, thus making this answer correct.