Consider the following reaction and statements:

${\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Br}}_2\right]}^{+}+{\mathrm{Br}}^{-}\to \left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3{\mathrm{Br}}_3\right]+{\mathrm{NH}}_3$

(i) Two isomers are produced if the reactant complex ion is a cis-isomer.

(ii) Two isomers are produced if the reactant complex ion is a trans-isomer.

(iii) Only one isomer is produced if the reactant complex ion is a trans-isomer.

(iv) Only one isomer is produced if the reactant complex ion is a cis-isomer.

The correct statements are