The co-ordination number of chromium in $\mathrm{K}\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_2\left(\mathrm{C}_2 \mathrm{O}_4\right)_2\right]$ is

• A

  $5$
• B

  $4$
• Correct answer
  C

  $6$
• D

  $3$

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