Sum to $n$ terms of the series $1^{3}+3.2^{3}+3^{3}+3.4^{3}+5^{3}$ $+\ldots .$, where $n$ is even, is
(A) $\frac{n^{2}\left(n^{2}-3 n+1\right)}{2}$
(B) $\frac{n^{2}\left(n^{2}+3 n+1\right)}{2}$
(C) $\frac{n^{2}\left(n^{2}+3 n+1\right)}{4}$
(D) None of these