Which oxidation reaction requires the coenzyme FAD because it involves oxidation of a carbon-carbon single bond to a double bond?

A)oxidation of isocitrate to $\alpha$ -ketoglutarate
B)oxidation of $\alpha$ -ketoglutarate to succinyl-CoA
C)oxidation of succinate to fumarate
D)oxidation of malate to oxaloacetate
E)oxidation of pyruvate to acetyl-CoA