Answer the following : (a) Which isomer of $ ext{C}_4 ext{H}_9 ext{Br}$ is most reactive towards $ ext{S}_ ext{N}1$ reaction ? (b) Predict the alkene that would be formed by dehydrohalogenation of 1-Bromo-1-methylcyclohexane. (c) Although chlorine shows strong $- ext{I}$ effect, yet it is ortho- and para-directing in electrophilic aromatic substitution reactions. Why ?