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
Folding of protein chain is due to : 
Select and explain. 
A. Amide bond, B. Hydrogen bonds, C. Phosphodiesterase bonds, D. Disulphide bond
B: Hydrogen bonds
Answer: B: Hydrogen bonds 
Explanation: B i.e. Hydrogen bond