This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
Essential pentosuria is due to deficiency of 
Select and explain. 
A. Gulonolactone oxidase, B. Phosphoglucomutase, C. Xylulose reductase, D. Fructokinase
C: Xylulose reductase
Answer: C: Xylulose reductase 
Explanation: Repeated question