Since an object is identical with itself 'being identical, it is called a reflexive relation and if a relation is transitive, symmetric and reflexive, then such a relation is called 'equivalence'. If so, what kind of relation is "different"?
A 'different' relation may be symmetric as well as transitive. But it cannot be reflexive. So, it is inequivalence. Therefore, 'Inequivalence' is the correct option.