Optical isomerism occurs when a molecule has a chiral center (carbon with four different substituents) and lacks a plane of symmetry. The compound must be non-superimposable on its mirror image.

For a compound to show optical activity, it must have at least one chiral carbon. A chiral carbon is denoted as $C^{*}$ and has four different atoms or groups attached.

After evaluating the given structures, the compound with a chiral carbon and no plane of symmetry is the one that exhibits optical isomerism.

Final Answer: The third compound (image with structure containing a chiral carbon) shows optical isomerism.