$\begin{array}{1 1} (1)\large\frac{1}{c^2} \bigg[G \frac{e^2}{4 \pi \in_0} \bigg]^{1/2} \\
(2) c^2 \bigg[G \frac{e^2}{4 \pi \in_0} \bigg]^{1/2} \\
(3)\large\frac{1}{c^2} \bigg[\frac{e^2}{G 4 \pi \in_0} \bigg]^{1/2} \\
(4) \large\frac{1}{c} G \large\frac{e^2}{4 \pi \in_0} \end{array} $