If the sum of $n$ terms of an A.P. is given by $S_n=(3n^2+2n)$,then its $n^{th}$ term is ________

Question

$\begin{array}{1 1}(A) \;6n+1\\(B)\;6n-1 \\(C)\;n+6 \\(D)\;n-6 \end{array}$