The correct option is B tripeptide
The amino acid unit having free −NH2 groups is called N-terminal end whereas, the amino acid unit with free −COOH group is called C-terminal end.
The structure is written with N-terminal end to the left and C-terminal end to the right.
At N-terminal or C-terminal further bond formation takes place and tri, tetra, pentapeptides are formed.
It is a tripeptide made from alanine, glycine and phenylalanine. It is abbreviated as Ala-Gly-Phe. The carboxyl group of alanine and the amino group of glycine combine to form one peptide bond. The second peptide linkage is formed between −COOH of glycine and −NH2 of phenylalanine.