Concept:Geometric isomerism occurs in alkenes where each carbon of the C=C bond has two different substituents.
Explanation:Hex-3-ene is
CH3CH2CH=CHCH2CH3. Each doubly bonded carbon is attached to a hydrogen atom and an ethyl group, which are different.
This allows cis-trans isomerism.
Hexane has no double bond, so it cannot show geometric isomerism.
Prop-1-ene has a terminal
CH2 group, so one doubly bonded carbon has two identical hydrogen atoms.
3-methylbut-1-ene also has a terminal
CH2 group, so geometric isomerism is not possible.
Answer:A. hex-3-ene