The Citric Acid Cycle Has Which Step as a Main $\rightarrow$

The citric acid cycle has which step as a main control?

A) step 3, isocitrate $\rightarrow$$\alpha$ -ketoglutarate
B) step 1, acetyl-CoA $\rightarrow$ citrate
C) step 7, fumarate $\rightarrow$ malate
D) step 8, malate $\rightarrow$ oxaloacetate