Review Question - QID 214271

A 6-month-old boy is referred to a geneticist because of failure to thrive and developmental delays. He was born at home and had late establishment of care around 3 months of age. At that time, he was found to have restricted joint motion as well as a weight in the bottom 10th percentile. Since then, he has continued to have decreased growth and was found on physical exam to have hepatosplenomegaly. Laboratory tests reveal high levels of hydrolases in the blood. The enzyme that is most likely defective in this patient is in which of the following classes?