Correct Answer - B
`underset("Ethylene chloride")(underset(Cl)underset(|)(C )H_(2)-underset(Cl)underset(|)(C )H_(2))overset(aq. KOH)rarr underset(OH)underset("| ")("C ")H_(2)-underset(OH)underset("| ")("C ")H_(2)`
`underset("Ethylidene dichloride")(CH_(3)-overset(Cl)overset(|)(C )H-Cl)overset(aq. KOH)rarr CH_(3)CHO`