d
$\mathrm{E}_{1}=\frac{\mathrm{KQ}_{1}}{\mathrm{R}_{1}^{2}}$
$\mathrm{E}_{2}=\frac{\mathrm{KQ}_{2}}{\mathrm{R}_{2}^{2}}$
$\frac{E_{1}}{E_{2}}=\frac{R_{1}}{R_{2}}$
$\cfrac{\frac{\mathrm{KQ}_{1}}{\mathrm{R}_{1}^{2}}}{\frac{\mathrm{KQ}_{2}}{\mathrm{R}_{2}^{2}}}=\frac{\mathrm{R}_{1}}{\mathrm{R}_{2}}$
$\frac{Q_{1}}{Q_{2}}=\frac{R_{1}^{3}}{R_{2}^{3}}$
$\frac{\mathrm{V}_{1}}{\mathrm{V}_{2}}=\frac{\mathrm{KQ}_{1} / \mathrm{R}_{1}}{\mathrm{KQ}_{2} / \mathrm{R}_{2}}=\frac{\mathrm{R}_{1}^{2}}{\mathrm{R}_{2}^{2}}$