This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
Creatinine is synthesized from: 
Select and explain. 
A. Glycine,arginine and methionine, B. Glycine and methionine, C. Ornithine and glycine, D. Thymine and ornithine
A: Glycine,arginine and methionine
Answer: A: Glycine,arginine and methionine 
Explanation: A Harper, 26lh ed, p. 268, Fig (31 - 6) & 25th ed, p. 354