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
Main enzyme for glycogen metabolism ? 
Select and explain. 
A. Glucose-6-phosphatase, B. Glycogen synthase, C. PFK - 1, D. None of the above
B: Glycogen synthase
Answer: B: Glycogen synthase 
Explanation: Ans. is 'b' i.e., Glycogen synthase