The correct option is D cis-2-butene and trans-2-butene isomers have the same structure and different arrangement of atoms or groups in space
Cis and Trans-isomers have the same structure but have different configuration (arrangement of atoms or groups in space)
Trans-alkenes are generally more stable than cis-alkenes due to less steric crowding.
In some cases, where H-bonding is possible, cis-alkenes are more stable relatively than trans-alkenes.