Which of the following is the first product of glycogenolysis?

Glycogenolysis involves three steps. First, the repetitive removal of glucose residues by phosphorylase breaking bonds between carbons 1 and 4, producing a glucose-1-phosphate molecule. Second, a glucan transferase enzyme moves three residues to the linear pa of the glycogen chain. Third, a debranching enzyme cleaves the carbons 1 and 6 bond. A final enzyme conves the resulting glucose-1-phosphate molecules into glucose-6-phosphate for entry into glycolysis. Ref: Janson L.W., Tischler M.E. (2012). Chapter 6. Carbohydrate Metabolism. In L.W. Janson, M.E. Tischler (Eds), The Big Picture: Medical Biochemistry.