This reaction involves the addition of HBr to an alkene, following Markovnikov's rule. The hydrogen adds to the less substituted carbon, and the bromine adds to the more substituted carbon. The alkene is unsymmetrical, with one carbon having two alkyl groups. The major product is the more stable tertiary carbocation intermediate, leading to 2-bromo-2-methylbutane.

The carbocation stability order is: tertiary > secondary > primary. The reaction mechanism is:

$\mathrm{Alkene}+\mathrm{HBr}\to \mathrm{Tertiary\; carbocation}\to \mathrm{Major\; product}$

Final Answer: The major product is the third option (2-bromo-2-methylbutane).