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
In which of the following tissues, is glycogen incapable of contributing directly to blood glucose? 
Select and explain. 
A. Liver, B. Muscle, C. Both, D. None
B: Muscle
Answer: B: Muscle 
Explanation: Only liver can replenish blood glucose through gluconeogenesis because glucose-6-phosphatase is present mainly in liver.Ref: DM Vasudevan, 7th edition