The group having isoelectronic species is :

Question

$\begin{array}{1 1} (1) O^{2−}, F^{−}, Na, Mg^{2+} \\ (2) O^{−}, F{−}, Na^{+}, Mg^{2+} \\ (3) O^{2−}, F^{−}, Na, Mg^{2+} \\ (4) O^{−}, F^{−}, Na, Mg^{+} \end{array}$