Answer:
Since acetyl-CoA is a 2-carbon compound, it is easier to remove electrons and produce CO2 from 2-carbon compounds than 3 or more carbon compounds. Although it is possible to oxidize the Acetyl group which has 2 carbons of acetyl CoA into 2 CO2 molecules, this process becomes much more difficult than adding the Acetyl group to a four carbon acid to form a six carbon acid (citrate). The citrate may then be sequentially oxidized to release two CO2 molecules.
Explanation: