In the conversion of pyruvate to acetyl CoA, which of the following statements accurately describe/s what happens to the third carbon atom? (Select all that apply.)
I. The third carbon atom is expelled as carbon dioxide (CO₂).
II. The third carbon atom is converted into acetyl CoA.
III. The third carbon atom is stored within the mitochondrial matrix.
IV. The third carbon atom is removed during the decarboxylation process.