Answer:
a. ADP
Step-by-step explanation:
Isocitrate dehydrogenase is an enzyme in citric acid cycle that occurs in mitochondrial matrix.
It catalyzes conversion of the isocitrate to the alpha-ketoglutarate and Carbon dioxide which occurs in a two step process.
IDH is regulated allosterically by the ADP positively in the mammals and inhibited by ATP, NADH.
The enzyme, IDH will not catalyze the reaction unless there are low levels of ADP.