This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: HMP Shunt Pathway, Fructose, Galactose Metabolism, Subject name: Biochemistry
Rate Limiting step of Pathway (Figure) is catalyzed by 
Select and explain. 
A. Glucose-6-phosphatase dehydrogenase, B. Gluconolactone hydrolase, C. 6-phospho-gluconate dehydrogenase, D. Transketolase
A: Glucose-6-phosphatase dehydrogenase
Answer: A: Glucose-6-phosphatase dehydrogenase 
Explanation: Glucose-6-phosphatase dehydrogenase (Pathway shown: Pentose Phosphate pathway/ Hexose monophosphate shunt pathway)