premise: Jacques Santer succeeded Jacques Delors as president of the European Commission in 1995, the second Luxembourger to hold this high office.
hypothesis: Jacques Santer and Jacques Delors were both presidents of the European Commission and both of them were from Luxembourg.
reason: Based on the text Jacques Santer succeeded Jacques Delors as president of the European Commission and also Jacques Santer was from Luxembourg. We don't know if Jacques Delors was from Luxembourg, maybe he was from France, which makes the statement neither definitely correct nor definitely incorrect. I think the system got confused, because the first part of the statement is correct and based on the text one can wrongfully assume that both Jacques Santer and Jacques Delors are Luxembourgers.