The catabolic process of converting carbohydrates to CO2 requires<u> oxidation</u> of carbon.
Explanation:
There are multiple definitions of reduction-oxidation. There is one that explains it with respect to oxygen, the other with respect to hydrogen and another with respect to electrons. The relevant one here is the one that explains it in terms of hydrogen. Oxidation is the removal of hydrogen while reduction is the addition of hydrogen. During repiration, the carbon loses the hydrogens attached to it and is therefore oxidized. These hydrogens attach themselves to oxygen which means oxygen is reduced.
