This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: TCA Cycle, Subject name: Biochemistry
[{'content': 'Which molecule is regarded as carrier of TCA cycle ? \nSelect and explain. \nA. Acetyl CoA, B. Oxaloacetate, C. Citrate, D. ATP', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Oxaloacetate is regarded as: Carrier of TCA cycle 1st substrate of TCA catalytic role in TCA Acetyl CoA is not glucogenic; not carrier, 1st substrate or intermediate of TCA cycle', 'role': 'assistant'}]