In Operator Grammar we are looking next token forward only but not backward.
In SLR(1) and LR(1) we look one token advance according to that actions(Shift or Reduce) actions performed.
In LR(K) lookahead K symbols.
One more is bottom level tokens having higher precedence that top level in parse tree.
Remember these two key points ,now first draw parse tre for any one string
In above prase tree a and c are at same level and having equall precedence.
a<.b ---b is bottom level and a is top level so it is correct.
c<.g---g is bottom level and c is top level.
a<.e---it is also correct.
c<.b---b is bottom level and c is top level but b is backward to c,so c may not look b.it is incorrect.
Hence Option should be D