Ligands with which linkage isomerism is possible

$\text{ A) }{\mathrm{NO}}_2$             $\text{ B) }{\mathrm{CN}}^{-}$           $\text{ C) }{\mathrm{SCN}}^{-}$

A) NO₂ B) CN^– C) SCN^– all ligands with which linkage isomerism is possible, because they have two donar atoms.