Which of the following is a cationic detergent? 

Cationic detergents are quaternary ammonium salts of amines with acetate, chlorides or bromides as anions. Cations are long-chain hydrocarbons having a positive charge on N atom. Example: Cetyltrimethylammonium bromide (Cationic detergent)

${\mathrm{C}}_{19}{\mathrm{H}}_{42}{\mathrm{N}}^{+}{\mathrm{Br}}^{-}$  (cationic detergent)

Sodium dodecyl benzene sulphonate (anionic detergent)

$\text{(1) }{\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_{10}{\mathrm{CH}}_2{\mathrm{OSO}}_3^{-}{\mathrm{Na}}^{+}$ Sodium lauryl sulphate (anionic detergent)

$\text{(2)}{\mathrm{C}}_{17}{\mathrm{H}}_{35}\mathrm{COONa}$ Sodium stearate (soap)