Integrate : $\int \large\frac{3x+1}{(3x^2+2x+1)^2}$$dx$

Question

$$\begin {array} {1 1} (a)\;\frac{1}{2}(3x^2+2x+1)+c \\ (b)\;(3x^2+2x+1)+c \\ (c)\;-\frac{1}{2}(3x^2+2x+1) +c \\ (d)\;None \end {array}$$