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
In which of the following step is ATP released? 
Select and explain. 
A. a) Phosphoenol pyruvate to pyruvate, B. b) Glyceraldehydes 3 phosphate to 1, 3, biphosphoglycerate, C. c) Fructose 6 phosphate to fructose 1, 6 biphosphate, D. d) Glucose to glucose 6 phosphate
A: a) Phosphoenol pyruvate to pyruvate
Answer: A: a) Phosphoenol pyruvate to pyruvate 
Explanation: Steps releasing ATP are-- 1, 3, biphosphoglycerate to 3 phosphoglycerate (1, 3 biphosphoglycerate Kinase)- Phosphoenol pyruvate to pyruvate( pyruvate kinase)- Succinyl CoA to Succinate ( Succinate Thiokinase)