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
Which of these is a denaturating substance: 
Select and explain. 
A. Guanosine, B. Guanidine, C. Glutamate, D. Glycine
B: Guanidine
Answer: B: Guanidine 
Explanation: B i.e. Guanidine