The correct option is
A chlorobenzene
Chlorination of benzene in the presence of a catalytic amount of Lewis acid such as ferric chloride produces chlorobenzene. The catalyst enhances the electrophilicity of the chlorine.
C6H6+Cl2FeCl3→C6H5Cl
Because chlorine is electronegative, C6H5Cl exhibits somewhat decreased susceptibility to further chlorination.