Basic Amino Acid Identification

Amino acids are the building blocks of proteins and play crucial roles in various biological processes. Each amino acid has a unique side chain that determines its properties. The side chains can be classified into different categories based on their chemical characteristics, such as being polar, non-polar, acidic, or basic. The behavior of amino acids in a protein structure can significantly affect the protein's function.

Which of the following amino acids presents a basic side chain?