The statement(s) that are correct about the species \( \mathrm{O}^{2-} \), \( \mathrm{F}^{-} \), \( \mathrm{Na}^{+} \) and \( \mathrm{Mg}^{2+} \).
(A) All are isoelectronic
(B) All have the same nuclear charge
(C) \( \mathrm{O}^{2-} \) has the largest ionic radii
(D) \( \mathrm{Mg}^{2+} \) has the smallest ionic radii
Choose the most appropriate answer from the options given below: