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
When muscle glycogen is used for anaerobic glycolysis, how many ATPs are formed? 
Select and explain. 
A. 2, B. 3, C. 4, D. 7
B: 3
Answer: B: 3 
Explanation: Normally anaerobic glycolysis produces 2 ATPs. But the end product of muscle glycogenolysis is glucose-6-phosphate. Glucose-6-phosphatase is absent in muscle. So the step catalysed by hexokinase / Glucokinase is not needed. Hence the answer is 3.