Which of the following does not exist ?

• Correct answer
  A

  $\left[\mathrm{SiCl}_6\right]^{2-}$
• B

  $\left[\mathrm{GeCl}_6\right]^{2-}$
• C

  $\left[\mathrm{SiF}_6\right]^{2-}$
• D

  $\left[\mathrm{Sn}(\mathrm{OH})_6\right]^{2-}$

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