Q.95 four equal positive charges q are fixed at the comers ofa square of side 'a'. what minimum work has to be done in moving charge-q from the centre of square

Q.95 Four equal positive charges q are fixed at the comers ofa square of side 'a'. What minimum work has to be done in moving charge-q from the centre of square to infinity? (a) E2 b) tEga TEga (c)4 TEa (d) V2g2 47TEa