Citrate synthase, one of the enzymes in the series of enzyme-catalyzed reactions known as...

Citrate synthase, one of the enzymes in the series of enzyme-catalyzed reactions known as the citric acid cycle (Section 18.7), catalyzes the synthesis of citric acid from oxaloacetic acid and acetyl-CoA. If the synthesis is carried out with acetyl-CoA that has radioactive carbon (14C) in the indicated position, the isomer shown here is obtained. (Note: 14C has a higher priority than 12C.)

a. Which stereoisomer of citric acid is synthesized, R or S?

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b. Why is the other stereoisomer not obtained?

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c. If the acetyl-CoA used in the synthesis does not contain 14C, will the product of the reaction be chiral or achiral?