This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Rate limiting step in HMP shunt ? \nSelect and explain. \nA. Glucose-6-phosphate - 6-phosphogluconolactone, B. 6-phosphogluconolactone - 6-phosphogluconate, C. 6-phosphogluconate - Ribulose-5-phosphate, D. Ribulose-5-phosphate - Xylulose-5-phosphate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Glucose-6-phosphate - 6-phosphogluconolactone', 'role': 'assistant'}]