Which of the following will not show geometrical isomerism?

1. 

2. 

3. 

4. 

HINT: If same groups are attached with any double bonded carbon atom then compound does not show geometrical isomerism.
 
In option (4), a carbon with double bond has two same functional groups (CH3) attached. The rotation around carbon will not produce a new compound. Hence, geometrical isomerism is not possible.