Question Detail

Geometrical (cis-trans) isomerism requires a carbon-carbon double bond where each carbon has two different substituents. Option C (written as CH₂CHCHCl) implies propene with a chlorine substituent. The corrected structure should be CH₃-CH=CH-Cl or similar. Among the choices, the compound with a double bond and non-identical groups on each carbon is the correct one. Option C is the only one with a double bond, though its formula is incorrectly written.