The sum of the series $\frac{1}{1+1^{2}+1^{4}}+\frac{2}{1+2^{2}+2^{4}}+\frac{3}{1+3^{2}+3^{4}}+\ldots$ to $n$ terms
is
(A) $\frac{n\left(n^{2}+1\right)}{n^{2}+n+1}$
(B) $\frac{n(n+1)}{2\left(n^{2}+n+1\right)}$
(C) $\frac{n\left(n^{2}-1\right)}{2\left(n^{2}+n+1\right)}$
(D) None of these