A thin, uniform rod of mass \(M\) and length \(L\) is pivoted about a frictionless horizontal axis perpendicular to the rod at a variable distance \(x\) from its center of mass, where \(0 < x \le \dfrac{L}{2}\). The rod is displaced by a small angle from its vertical equilibrium position and released from rest. Which of the following best describes the qualitative shape of the graph of the period \(T\) of small oscillations as a function of the pivot distance \(x\)?