Two concentric, thin spherical conducting shells have radii \(R\) and \(3R\). The inner shell carries a net charge \(+Q\), and the outer shell carries a net charge \(-2Q\). The electric potential is defined to be zero at infinity (\(V(\infty) = 0\)). Which of the following correctly describes the qualitative behavior of the electric potential \(V(r)\) as a function of radial distance \(r\) from the common center?