This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
[{'content': 'Von Gierke disease enzyme deficient \nSelect and explain. \nA. Glucose 6 phosphatase, B. Branching enzyme, C. Debranching enzyme, D. Phospharylase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Repeated question', 'role': 'assistant'}]