A particle with mass \(m\) and positive charge \(q\) is launched with speed \(v\) into a region of uniform magnetic field of magnitude \(B\). The velocity vector of the particle makes an angle \(\theta\) with the direction of the magnetic field, where \(0 < \theta < \dfrac{\pi}{2}\). The particle undergoes helical motion characterized by a trajectory radius \(R\) and a pitch \(p\), defined as the axial distance traveled parallel to the magnetic field during one complete revolution. Which of the following is a correct expression for the ratio \(\dfrac{p}{R}\) of the pitch to the radius of the trajectory?