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
The 3 dimensional shape of a protein is maintained mainly by: 
Select and explain. 
A. Strong covalent interactions, B. Interactions with other proteins, C. Multiple weak interactions, D. Interactions with prosthetic groups
C: Multiple weak interactions
Answer: C: Multiple weak interactions 
Explanation: C i.e. Multiple weak interaction