An element belongs to particular group is related to the number of electrons present in the outer shell of the atoms. In given case, group is 2, therefore, number of valence electrons is 2 implies it has ability to lose two electrons to get +2 charge.
[tex]A\rightarrow A^{+2}+2e^{-}[/tex]
Therefore, ion formed after removal of two electrons is [tex]A^{2+}[/tex].
Hence, option (D) is the correct answer.
