An infinitely long, flat insulating ribbon of width \(w\) lies in the \(xy\)-plane, extending parallel to the \(y\)-axis from \(x = 0\) to \(x = w\). The ribbon carries a uniform surface charge density \(\sigma\). A point \(P\) lies in the same plane on the \(x\)-axis at a distance \(d\) from the nearest edge of the ribbon, at coordinates \((-d, 0, 0)\). Which of the following expressions represents the magnitude of the electric field at point \(P\)?