Option (ii) is the answer.
Vicinal dihalides are formed when a halogen reacts with an alkene to form compounds with halogen on neighbouring carbons. In terms of yearly output, 1, 2- dichloroethane outnumbers all other organohalogen chemicals, averaging 20 million tonnes per year.
$
\mathrm{CH}_{2}=\mathrm{CH}_{2}+\mathrm{Cl}_{2} \rightarrow \mathrm{ClCH}_{2} \mathrm{CH}_{4} \mathrm{Cl}
$
ethylne chlorine 1, 2- Dichloroethane