The alkene that exhibits geometrical isomerism is:

Geometrical isomerism (cis-trans) occurs in alkenes when each of the two doubly bonded carbon atoms is attached to two different groups.Propene: ${\text{CH}}_3\text{CH}={\text{CH}}_2$ (One $C$ has two $H$ atoms).2-methylpropene: $({\text{CH}}_3{)}_2\text{C}={\text{CH}}_2$ (Both $C$ have identical groups).2-butene: ${\text{CH}}_3\text{CH}={\text{CHCH}}_3$. Each doubly bonded carbon is attached to $H$ and ${\text{CH}}_3$. It exhibits cis and trans forms.2-methyl-2-butene: $({\text{CH}}_3{)}_2\text{C}={\text{CHCH}}_3$ (One $C$ has two ${\text{CH}}_3$ groups).