Which of the following pairs has the same size ?

Options

A. `Zr^(4+), 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 lanthaniod contraction.