Two Concentric Conducting Spherical Shells Have Radii R and R

Two concentric conducting spherical shells have radii r and R (> r) and charges q and Q, respectively. It can be shown that the electric potential difference between the two shells, V_R - V_r, is proportional to q(1/R - 1/r) . If a thin conducting string connects the two shells, charge

A) would flow from the smaller to the larger sphere.
B) would flow from the larger to the smaller sphere.
C) would flow from the smaller to the larger sphere or from the larger to the smaller sphere depending on the signs of the charges on the spheres.
D) would not flow between the spheres at all.
E) More information is needed to work out the answer.