Answer: C
Explanation:
Pyruvate dehydrogenase complex (PDH) is covalently modified by phosphorylation by PDH kinase and dephosphorylation by PDH phosphatase.
The dephosphorylated form of the enzyme is active. Hence activators of PDH kinase like ATP, NADH and acetyl CoA inhibits the PDH reaction
PDH phosphatase is activated by Ca++, Mg++ and AMP; this will increase the rate of PDH reaction where as PDH kinase is inhibited by Ca++. When there is adequate ATP and acetyl CoA the enzyme is inhibited.