Given below are two statements, one is labelled as

Assertion (A): The ionic radii of $O^{-2}$^- and $M{g}^{+2}$ are same.

Reason (R): Both and are isoelectronic species.

correct answer from the options given below

Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Assertion is false and Reason is true

 Assertion is true and Reason is false

Both Assertion and Reason are true and Reason is not the correct explanation of Assertion.