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
Compound that joints glycolysis with glycogenesis and glycogenolysis is 
Select and explain. 
A. Glucose 1, 6 biphosphate, B. Glucose 1 phosphate, C. Glucose 6 phosphate, D. Fructose 1, 6 biphosphate
C: Glucose 6 phosphate
Answer: C: Glucose 6 phosphate 
Explanation: Repeated question