Substrate level phosphorylation is seen in the conversion of: (A) Acetoacetate to α-keto glutarate, (B) Succinyl CoA to Succinate, (C) Fumarate to malate, (D) Succinate to fumarate
Answer is B. Substrate level phosphorylation

It is the production of ATP (or GTP) at substrate level without participation of electron transport chain.
It occurs in glycolysis and citric acid cycle, at following steps :-