Hydrocarbons

Among the following rules, the one which is
applied in the given reaction is

\(\mathrm{CH}_3 \mathrm{CHBrCH}_2 \mathrm{CH}_3 \xrightarrow{\text { Alc. } \mathrm{KOH}}\)

I. \(\mathrm{CH}_3 \mathrm{CH}=\mathrm{CHCH}_3\) (major product)

II. \(\mathrm{CH}_2=\mathrm{CHCH}_2 \mathrm{CH}_3\) (minor product)