Which amino acid has an R group containing a phenol moiety?
Phenylalanine accurately describes the structural composition or molecular organization asked about in this question. In Amino_Acids_Structure, knowledge of molecular structure is directly linked to understanding biological function. The specific arrangement of chemical components in Phenylalanine determines its physical properties, biological activity, and interactions with other molecules. The other options (Tyrosine, Tryptophan, and Serine) describe different structural arrangements, incorrect stoichiometry, or compositions of different biological molecules.
Ref: Campbell Biology, Urry et al., 12th Ed.