Which of the following compounds forms 1-bromo-1-methylcyclohexane when treated with HBr ?

Step-by-step solution

Electrophilic addition of HBr to alkenes follows Markovnikov's rule, with hydrogen adding to the carbon of the double bond with more hydrogen atoms. The product 1-bromo-1-methylcyclohexane has both bromine and methyl substituents on the same carbon. 1-Methylcyclohexene (Option A) reacts with HBr to form a tertiary carbocation at C1, stabilized by the methyl group and ring structure. Bromide addition yields 1-bromo-1-methylcyclohexane. 3-Methylcyclohexene and 4-methylcyclohexene (Options B and C) form secondary carb