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.