This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Tertiary structure of a protein describes 
Select and explain. 
A. The order of amino acids, B. Location of disulphide bonds, C. Loop regions of proteins, D. The ways of protein folding
D: The ways of protein folding
Answer: D: The ways of protein folding 
Explanation: 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