The Citric Acid cycle itself can be divided into three stages called Pyruvate transport, CO2 emission stage, and the oxaloacetate reformation stage. Where would you draw the line dividing the three stages and why?

a) After Pyruvate transport; Pyruvate enters the cycle
b) After CO2 emission stage; carbon dioxide is released
c) After the oxaloacetate reformation stage; oxaloacetate is regenerated
d) After the first complete rotation of the cycle; a new cycle begins