Finkelstein reaction involves

Replacement of ${\mathrm{CI}}^{-} \mathrm{by} {\mathrm{I}}^{-}$

Exchange of ${\mathrm{Cl}}^{-} \mathrm{by} {\mathrm{Br}}^{-}$

Formation of volatile copper chlorides to burn with a green-edged flame

Exchange of ${\mathrm{Br}}^{-} \mathrm{by} {\mathrm{CI}}^{-}$