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 of the following vitamins is not involved in TCA cycle? \nSelect and explain. \nA. Riboflavin, B. Thiamine, C. Niacin, D. Pyridoxine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Vitamins in TCA cycle are :\n\nThiamine (B1)\nRiboflavin (B2)\nNiacian (B3)\nPantothenic acid (B5)', 'role': 'assistant'}]