If we notice the productions of this grammar
S->aSb | bSa | SS | ∈
these productions will always produce number of a's and b's equal.
Also , S-> SaS this production may add more number of a's to number of a's and b's produced by the productions above.
So all, in all this grammar is generating Number of a's = Number of b's or Number of a's are greater than number of b's
If we check option (d), it has more number of b's than a which surely cannot in no way be generated by this grammar.