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': 'Muscle glycogen, which cannot contribute to blood glucose due to the absence of which enzyme? \nSelect and explain. \nA. Phosphoglutamase, B. Branching enzyme, C. Debranching enzyme, D. Glucose-6-phosphotase', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]