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
Von Gierke disease enzyme deficient 
Select and explain. 
A. Glucose 6 phosphatase, B. Branching enzyme, C. Debranching enzyme, D. Phospharylase
A: Glucose 6 phosphatase
Answer: A: Glucose 6 phosphatase 
Explanation: Repeated question