The main product of glycogenolysis is glucose-1-phosphate, which is rapidly converted to glucose-6-phosphate. In the liver, glucose-6-phosphate is further dephosphorylated by glucose-6-phosphatase to release free glucose into the bloodstream, maintaining blood glucose levels. This is critical during fasting or surgical stress when glucose demand increases. Other options like lactate, fructose, and pyruvate are products of different metabolic pathways (e.g., glycolysis). Therefore, the correct product of glycogen breakdown that can be exported systemically is glucose.

Reference: Harper’s Illustrated Biochemistry, Murray et al., 31st Edition.