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
. Muscle cannot make use of glycogen for energy because of deficiency of: 
Select and explain. 
A. Glucokinase, B. Phosphoglucomutase, C. G-6-phosphatase, D. Muscle phosphorylase
C: G-6-phosphatase
Answer: C: G-6-phosphatase 
Explanation: C i.e. G- 6- Phosphatase