A solid uniform sphere of mass \(M\) and radius \(R\) rolls without slipping along a horizontal surface with a constant center-of-mass speed \(v\). The rotational inertia of a solid uniform sphere about an axis through its center is \(I = \dfrac{2}{5}MR^2\). Which of the following is the ratio of the sphere’s rotational kinetic energy to its total kinetic energy?