In Which of the Following Pairs of Metabolic Carboxylate Ions $\alpha$

In which of the following pairs of metabolic carboxylate ions are both members of the pair derivatives of succinic acid?

A) malate, fumarate
B) oxaloacetate, citrate
C) fumarate, $\alpha$ -ketoglutarate
D) ( $\alpha$ -ketoglutarate, citrate)