Tertiary structure of a protein describes: (A) The order of amino acids, (B) Location of disulphide bonds, (C) Loop regions of proteins, (D) The ways of protein folding
Answer is D. Secondary structure denotes the configurational relationship between residues which are about 3–4 amino acids apart; or secondary level defines the organization at immediate vicinity of amino acids.
The tertiary structure denotes three dimensional structure of the whole protein.

Reference: Vasudevan 7th  ed, pg 38