Which enzyme of the Krebs (TCA) cycle is different from the others with respect to its location and where is it located?

The correct answer to this question is Succinate dehydrogenase, inner mitochondrial membrane.
Succinate dehydrogenase, also known as succinate-coenzyme Q reductase or respiratory Complex II, is an enzyme found in the inner mitochondrial membrane. It is the only enzyme that is found both in the Citric acid cycle (Kreb’s cycle) and in the electron transport chain.

In the citric cycle, succinate dehydrogenase is the enzymes that catalyze the oxidation of succinate into fumarate. In the electron transport chain, the enzyme donates electrons from FADH2 to aid the reduction of ubiquinone to ubiquinol.

In summary, of all the enzymes that participate in the Kreb’s cycle, only succinate dehydrogenase can be found in inner mitochondria.