Addition of HCl to 2-methyl-2-butene mainly gives

Question

$\begin{array}{1 1}(a)\;\text{1-chloro-2-methylbutane}\\(b)\;\text{2-chloro-2-methylbutane}\\(c)\;\text{2-chlorobutane}\\(d)\;\text{1-chlorobutane}\end{array}$