A point particle with positive charge \(+q\) is held in a vacuum at a distance \(d\) from the flat surface of a semi-infinite, neutral dielectric material with dielectric constant \(\kappa\) (where \(\kappa > 1\)). The polarization of the dielectric surface creates an attractive electrostatic force on the point charge that can be modeled using an effective image charge \(q' = -q\left(\dfrac{\kappa - 1}{\kappa + 1}\right)\) located inside the dielectric at a perpendicular distance \(d\) from the boundary, directly opposite \(+q\). Which of the following expressions represents the magnitude of the attractive electrostatic force exerted on the point charge \(+q\) by the polarized dielectric?