What are the three components of a nucleotide?

The correct identification of the three components of a nucleotide is indeed nitrogenous base, sugar, and phosphate group. Nucleotides serve as the building blocks of nucleic acids like DNA and RNA, which are essential for storing and transferring genetic information.

The nitrogenous base is a critical component that can be one of several types, including adenine, thymine, cytosine, guanine, or uracil (in RNA). This base is responsible for the encoding of genetic information. The sugar component, which can either be ribose (in RNA) or deoxyribose (in DNA), forms the backbone of the nucleic acid structure alongside the phosphate group, which links adjacent nucleotides through phosphodiester bonds.

In contrast, the other options contain incorrect components that do not pertain to nucleotides. For instance, amino acids are the building blocks of proteins, not nucleotides, and fatty acids and glycerol are components of lipids, which are entirely different molecules. Option D mentions base, acid, and alcohol, which do not relate to the structure of nucleotides either. Thus, A correctly outlines the fundamental structure of a nucleotide.