The equation of the circle concentric with the circle $x^2+y^2-6x+12y+15=0$ and of double its area is :

Question

$$\begin {array} {1 1} (1)\;x^2+y^2-6x+12y-15=0 & \quad (2)\;x^2+y^2-6x+12y-30=0 \\ (3)\;x^2+y^2-6x+12y-25=0 & \quad (4)\;x^2+y^2-6x+12y-20=0 \end {array}$$