When vicinal dibromide is heated with KOH in ethanol$(~{200}^{o}C)$  , double dehydrohalogenation takes place giving alkyne. Which of the following fails to give alkyne according to this procedure?

Triple bond can not be formed here in option (c) between the carbons bearing bromine atoms because if triple bond will be formed, the valency of carbon atom will not satisfied. All other compound give dehydrohalogenation to give alkyne