\(A):(\frac{1}{5}) < (\frac{1}{x+1})< (\frac{1}{2})\)
\(2<(x+1)<5\)
\(1<x<4\)
Thus, possible values of \(x\) are : 2, 3 and since there is not a unique value, hence this statement alone is insufficient.
\(B);(x-3)(x-4)=0\)
Similarly, this statement alone is also not sufficient. But by combining both statements, we get:\(x=3 \) and \(x^{2} =9\)
The correct option is (C): If the question can be answered by using both the statements together but cannot be answered by using either statement alone.