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': "Which enzyme catalyses substrate level phosphorylation in Kreb's cycle? \nSelect and explain. \nA. ∝ Ketoglutarate dehydrogenase, B. Succinate thiokinase, C. Succinate dehydrogenase, D. Isocitrate dehydrogenase", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Succinate thiokinase catalyses substrate level phosphorylation of TCA cycle. It is the only enzyme of TCA cycle doing that.', 'role': 'assistant'}]