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 steps, ATP is released? 
Select and explain. 
A. Phosphoenol pyruvate to pyruvate, B. Glyceraldehyde-3-phosphate to 1,3 bisphosphoglycerate, C. Fructose-6-phosphate to fructose 1,6 bisphosphate, D. Glucose to glucose-6-phosphate
A: Phosphoenol pyruvate to pyruvate
Answer: A: Phosphoenol pyruvate to pyruvate 
Explanation: Steps releasing ATP at the level of substrate:

1, 3 Bisphosphoglycerate to 3-Phosphoglycerate (1, 3 Bisphosphoglycerate Kinase)
Phosphoenolpyruvate to Pyruvate (Pyruvate Kinase)
Succinyl CoA to Succinate (Succinate Thiokinase)