The tertiary structure of a protein is the a. organization of a polypeptide chain into an α-helix or β-pleated sheet b. order in which amino acids are joined in a polypeptide chain. c. unique three-dimensional shape of the fully folded polypeptide d. overall protein structure resulting from the aggregation of two or more polypeptide subunits

Answer;

C. Unique three-dimensional shape of the fully folded polypeptide

The tertiary structure of a protein is the unique three-dimensional shape of the fully folded polypeptide

Explanation;

A protein is a functional biological molecule that is made up of one or more polypeptides that are folded/coiled into a specific structure.

-As the secondary structure becomes established due to the primary structure, a polypeptide folds and refolds upon itself to assume a complex three-dimensional shape called the protein tertiary structure. Tertiary structure results from the interactions between the side chains (R groups) of the various amino acids.