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': 'The commonest enzyme deficiency is of: \nSelect and explain. \nA. Glucose-1-phosphatase, B. Glucose-6-phosphatase, C. Carbonic anhydrase, D. Cystathione synthetase', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Glucose-6-phosphatase', 'role': 'assistant'}]