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
[{'content': 'Threonine is metabolised to: \nSelect and explain. \nA. Lysine, B. Arginine, C. Ornithine, D. Glycine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Threonine aldolase cleaves threonine to acetaldehyde and glycine. Oxidation of acetaldehyde to acetate is followed by formation of acetyl-CoA. Ref: Harper 28th edition, chapter 29.', 'role': 'assistant'}]