Tricarboxylic acid cycle to be continuous requires the regeneration of: (A) Pyruvic acid, (B) oxaloacetic acid, (C) α-oxoglutaric acid, (D) Malic acid
Answer is B. Oxaloacetate may be viewed as a catalyst, which enters into the reaction, causes complete oxidation of acetyl CoA and comes out of it without any change.
Reference: Vasudevan 7th  ed, pg 249