In the following structure, the double bonds are marked as $\mathrm{I},\hspace{0.17em}\mathrm{II}, \mathrm{III}$ and $\mathrm{IV}$. 



 Geometrical isomerism is not possible at the site(s):

• A

  $\mathrm{I}$ and $\mathrm{III}$
• B

  $\mathrm{III}$
• Correct answer
  C

  $\mathrm{I}$
• D

  $\mathrm{III}$ and $\mathrm{IV}$

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