An electric dipole is kept on the axis of a uniformly charged ring at distance $\sqrt{2}\mathrm{R}$ from the centre of the ring. The direction of the dipole moment is along the axis. The dipole moment is p, charge of the ring is Q and radius of the ring is R. The force on the dipole is

• A

  $\frac{\mathrm{pQ}}{3{\mathrm{\pi \epsilon }}_0\sqrt{3}{\mathrm{R}}^2}$

• B

  $\frac{4\mathrm{pQ}}{3{\mathrm{\pi \epsilon }}_0\sqrt{3}{\mathrm{R}}^2}$

• C

  $\frac{\mathrm{pQ}}{3{\mathrm{\pi \epsilon }}_0{\mathrm{R}}^2}$

• D

  zero