Four equal point charges Q each are placed in the xy plane at (0,2), (4,2), (4,−2) and (0,−2). The work required to put a fifth charge Q at the origin of the coordinate system will be:
a. 4πϵ0Q2(1+31)
b. 4πϵ0Q2(1+51)
c. 22πϵ0Q2
d. 4πϵ0Q2