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A 2-year-old boy presents to his pediatrician with hepatosplenomegaly, failure to thrive, and progressive central nervous system deterioration. On ophthalmoscopic exam a cherry-red macula is noted. A bone marrow biopsy specimen is shown in the image. The pediatrician suspects that the boy will die by 3 years of age.
Which of the following is the function of the metabolic enzyme deficient in this patient?
A. Converts ceramide trihexoside to lactosyl cerebroside
B. Converts galactocerebroside to cerebroside
C. Converts ganglioside M2 to ganglioside M3
D. Converts glucocerebroside to ceramide
E. Converts sphingomyelin to ceramide
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