a
Anti-Markownikoff addition is possible only in case of \(HBr\) and not in \(HCl\) and \(HI\) . In \(HBr\) both the chain initiation and propagation steps are exothermic, while in \(HCl,\) first step is exothermic, and second step is endothermic and in \(HI,\) no step is exothermic. Hence \(HCl\) and \(HI\) do not undergo anti-Markownikoff's addition.