Two identical thin ring, each of radius R meters, are coaxially placed a distance R metres apart. If `Q_1` coulomb, and `Q_2` coulomb, are repectively the charges uniformly spread on the two rings, the work done in moving a charge q from the centre of one ring to that of the other is
A. Zero
B. `(q(Q_(1)-Q_(2))(sqrt(2)-1))/(sqrt(2).4piepsilon_(0)R)`
C. `(2sqrt(2)(Q_(1)+Q_(2)))/(4 pi epsilon_(0)R)`
D. `(q(Q_(1)+Q_(2))(sqrt(2)+1))/(sqrt(2).4 pi epsilon_(0)R)`
