A rectangular conducting slab has length \(L\), width \(w\), and thickness \(t\). A steady current \(I\) flows along the length of the slab, which is placed in a uniform magnetic field of magnitude \(B\) directed perpendicular to the face bounded by \(L\) and \(w\). In the steady state, charge accumulation on opposite side faces separated by distance \(w\) establishes a Hall potential difference \(V_H\). Which of the following expressions correctly gives the magnitude of the drift velocity \(v_d\) of the charge carriers in terms of the given quantities?