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
Substrate level phosphorylation is by 
Select and explain. 
A. a) Pyruvate kinase, B. b) Phosphofructokinase, C. c) Hexokinase, D. d) ATP synthase
A: a) Pyruvate kinase
Answer: A: a) Pyruvate kinase 
Explanation: substrate level phosphorylation-- Enzyme phosphoglycerate kinase- Enzyme pyruvate kinase.