Which of the following is an example of a positive ion and negative ion that is isoelectronic with Argon

Options

A. `K^(+)` and `Cl^(-)` or `Ca^(2+)` and `S^(2-)`
B. `Na^(+)` and `F^(-)` or `Mg^(2+)` and `O^(2-)`
C. `K^(+)` and `I^(-)` or `Mg^(2+)` and `S^(2-)`
D. `K^(+)` and `I^(-)` or `Ca^(2+)` and `O^(2-)`

Answer

A