Although the pyruvate dehydrogenase complex is subject io allosteric control, especially inhibition by reaction products, the main regulatory process controlling the enzymes activity in eukaryotes is

a. high energy charge switches the pyruvate dehydrogenase complex on.
b. phosphorylation by atp that turns on the complex and dephosphorylation that turns it off.
c. phosphorylation by atp that turns off the complex and dephosphorylation that turns it on.
d. exchange of adp and atp on the pyruvate dehydrogenase complex.
e. reversibility of the formation of acetyl coa from pyruvate.