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

• A
  $(B), (C)$ and $(D)$ only
• B
  $(A), (B), (C)$ and $(D)$
• C
  $(C)$ and $(D)$ only
• D
  $(A), (C)$ and $(D)$ only