A planar rectangular coil with \(N\) tightly wound turns has a width \(w\) and a height \(h\), carrying a steady electric current \(I\). The coil is placed in a uniform horizontal magnetic field of magnitude \(B\) and is free to rotate about a fixed vertical axis that passes through the midpoints of its top and bottom horizontal segments of length \(w\). As viewed from above, the plane of the coil makes an angle \(\theta\) with the direction of the magnetic field, where \(0 \le \theta < \dfrac{\pi}{2}\). Which of the following expressions represents the magnitude of the net magnetic torque exerted on the coil about the vertical rotation axis?