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
How many ATPs are produced in the conversion of phosphoenolpyruvate to citrate, including ATP formed from the oxidative phosphorylation of reduced coenzymes? 
Select and explain. 
A. 1, B. 2, C. 4, D. 6
C: 4
Answer: C: 4 
Explanation: One ATP is formed in the conversion of PEP to pyruvate, and one NADH (equivalent of three ATPs) is formed in the oxidative decarboxylation of pyruvate to acetyl CoA. Ref: Bender D.A., Mayes P.A. (2011). Chapter 17. The Citric Acid Cycle: The Catabolism of Acetyl-CoA. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.