The conversion of pyruvate to acetyl-CoA .
a. requires the addition of CO2
b. occurs in the mitochondria of the cell and is irreversible
c. occurs in the nucleus of the cell
d. is needed for red blood cell production

Explanation:

Sugars and fats are both degraded to acetyl CoA in the cell (mitochondria).

Glucose is degraded into pyruvate by various enzymes in the cytosol in both eukaryotes as well as prokaryotes. Pyruvate is further degraded into acetyl-CoA in the mitochondria in eukaryotes.

As pyruvate, which is generated in the cytosol is moves into mitochondria and is converted into acetyl-CoA.

In mitochondria, Acetyl-CoA is further enter into TCA cycle (also known as Krebs cycle) used in the production of FADH2, NADH2 and ATP.

In the presence of O₂, energy is generated by electron transport chain(ETC).