Allyl chloride on dehydrochlorination gives :

The correct answer is option 1. Propadiene.

Allylic carbon is the carbon atom which is bonded to a \(sp^2\) hybridized carbon atom. In case of allyl chloride, a chlorine atom is attached to the allylic carbon. Hence the structure of allyl chloride is

Dehydrochlorination is a type of elimination reaction that eliminates a molecule of hydrogen chloride from a given substrate resulting in the formation of an alkene.

Hence in the given substrate i.e. allyl chloride a molecule of hydrogen chloride is removed (\(Cl\) is removed from the \(\alpha \) carbon and H is removed from the \(\beta \) carbon) resulting in the formation of an allene.