Wilkinson’s catalyst is used in hydrogenation of alkenes. Formula of Wilkinson's catalyst is

• A

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

• B

  ${\mathrm{K}}_2\left[{\mathrm{HgI}}_4\right]$

• C

  $\left[\mathrm{RhCl}{\left({\mathrm{PPh}}_3\right)}_3\right]$

• D

  ${\mathrm{K}}_2\left[{\mathrm{PtCl}}_3\left({\mathrm{C}}_2{\mathrm{H}}_4\right)\right]$