Four equal point charges Q each are placed in the x y plane at (0, 2), (4, 2), (4, -2) and (0, -2). The work required to put a fifth charge Q at the…

Four equal point charges Q each are placed in the $\displaystyle x y$ plane at $\displaystyle (0, 2)$, $\displaystyle (4, 2)$, $\displaystyle (4, -2)$ and $\displaystyle (0, -2)$. The work required to put a fifth charge Q at the origin of the coordinate system will be :