This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fuel in Fed, Fasting and Starvation, Subject name: Biochemistry
[{'content': 'Creatinine is the breakdown product of: \nSelect and explain. \nA. Adenosine triphosphate, B. Purine nucleotides, C. Pyrimidine nucleotides, D. Creatine phosphate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Creatinine is the breakdown product of creatine phosphate This reaction occurs in muscles & does not involve any enzyme.', 'role': 'assistant'}]