Which of the following pairs has the same size ?

Options

A. `Zr^(+) , Hf^(4+)`
B. `Zn^(2+) , Hf^(4+)`
C. `Fe^(2+) , Ni^(2+)`
D. `Zr^(4+) , Ti^(4+)`

Answer

A

Explanation

`Zr^(4+)` and `Hf^(4+)` have similar ionic radii due to lanthanoid contraction .