The correct option is D C2H4
There are two types of elimination reaction,
1. α− Elimination reaction
2. β− Elimination reaction
In α− Elimination reaction, the leaving group and the proton are removed from the same α− carbon which leads to reactive carbene intermediate.
In β− Elimination reaction, the leaving group and the proton are removed from the adjacent atoms i.e., leaving group from α− carbon and proton from β− carbon. It leads to the formation of alkene compounds.
We know that,
When ethyl chloride is heated in presence of alcoholic KOH it undergo dehydrohalogenation to give alkene product. This reaction is a β− Elimination reaction.
Thus, in the given reaction ethene (C2H4) is produced.