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 amino acids are present in collagen? 
Select and explain. 
A. Glycine and cysteine, B. Glycine and proline, C. Glycine and arginine, D. Arginine and tryptophan
B: Glycine and proline
Answer: B: Glycine and proline 
Explanation: The amino acid present in large quantities in collagen are GLYCINE, PROLINE and HYDROXYPROLINE.
Approximately 1/3rd of the amino acid are contributed by Glycine i.e every 3rd amino acid in collagen is GLYCINE.
Reference :- Satyanarayana 4th Edition, Pg no. 488