Identify the option that includes all the reactions of the Krebs cycle during which oxidative decarboxylation occurs. 
M. oxaloacetate to citrate 
N. citrate to alpha-ketoglutarate 
O. alpha-ketoglutarate to succinyl CoA
P. oxaloacetate to fumarate 
Q. fumarate to malate 
R. malate to oxaloacetate

• A. M, N, O and P
• B. N, O, P and R
• C. N and O
• D. N, O, and R

Answer: (C)