A small bead of mass \(m\) and positive charge \(q\) is constrained to move along a frictionless, nonconducting horizontal track aligned with the \(x\)-axis. An arrangement of fixed external charges produces an electric potential along the axis given by the function \(V(x) = \alpha x^2\), where \(\alpha\) is a positive constant and \(V = 0\) at \(x = 0\). The bead is released from rest at a small initial displacement \(x = x_0\). Which of the following expressions represents the period \(T\) of the resulting oscillation of the bead?