The complex $\left[\mathrm{PtCl} \mathrm{C}_{2}(\mathrm{en})_{2}\right]^{2+}$ ion shows

• A

  structural isomerism only
• B

  optical isomerism only
• Correct answer
  C

  geometrical and optical isomerism
• D

  geometrical isomerism only

Solution

$\left[\mathrm{PtCl}_{2}(\mathrm{en})_{2}\right]^{2+}$ complex forms geometrical isomers (cis and trans). Trans-isomer does not show optical isomerism, since it is symmetrical while cis-isomer shows optical isomerism as it is unsymmetrical.

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