Four statements for the following reaction are given below.
$$[\text{CoCl}_2(\text{NH}_3)_4]^+ + \text{Cl}^- \rightarrow [\text{CoCl}_3(\text{NH}_3)_3] + \text{NH}_3$$
(I) only one isomer is produced if the reactant complex ion is a trans isomer
(II) three isomers are produced if the reactant complex ion is a cis isomer
(III) two isomers are produced if the reactant complex ion is a trans isomer
(IV) two isomers are produced if the reactant complex ion is cis isomer.
The correct statements are