Answer:
C is the correct option.
Explanation:
Glycolysis is the standard way for the formation of acetyl-CoA, from glucose.
Second, beta-oxidation of fatty acids generates 2 acetyl-coA molecules per cycle.
Finally, the degradation of amino acids generates intermediates of the Krebbs cycle. Occasionally Leucine, tryptophan and isoleucine are directly catalysed in acetyl-CoA.