A 6-month-old male is evaluated for poor growth and weight gain. The mother insists that she has fed this child in the same manner as her previous children, who are both healthy. On exam, you notice significant growth retardation and hepatomegaly. Labs reveal hypoglycemia. A liver biopsy demonstrates accumulation of small chain dextrin-like material in the cytosol of the infant’s hepatocytes. Which of the following enzymes is most likely deficient?

a) Acid maltase

b) Debranching enzyme

c) Glucose-6-phosphatase

d) Glycogen phosphorylase

e) Pyruvate kinase