The sum of $n$ terms of $m$ A.P.s are $S_{1}, S_{2}, S_{3}, \ldots, S_{m}$, If the first term and common difference are $1,2,3, \ldots, m$ respectively, then $S_{1}+S_{2}+S_{3}+\ldots+S_{m}=$
(A) $\frac{1}{4} m n(m+1)(n+1)$
(B) $\frac{1}{2} m n(m+1)(n+1)$
(C) $m n(m+1)(n+1)$
(D) None of these