Square-planar geometry is shown by

• Correct answer
  A

  $\left[\mathrm{PtCl}_2\left(\mathrm{NH}_3\right)_2\right]$
• B

  $\left[\mathrm{NiCl}_4\right]^{2-}$
• C

  $\mathrm{MnO}_4^{-}$
• D

  $\mathrm{CrO}_4^{2-}$

Solution

$$ \text { }\left[\mathrm{PtCl}_2\left(\mathrm{NH}_3\right)_2\right] \text { has square planar geometry. } $$

Hence, the correct answer is option: 'A'.