Which from the following ligands is able to form linkage isomers?

Complexes $[Co(NH_3)_5SO_4]Br$ and $[Co(NH_3)_5Br]SO_4$ can be distinguished by

The complexes $[Co(NH_3)_5Br]SO_4$ and $[Co(NH_3)_5SO_4]Br$ are examples of which type of isomerism?

The complex that can show optical activity is:

Total number of cis $N-Mn-Cl$ bond angles (that is,$Mn-N$ and $Mn-Cl$ bonds in cis positions) present in $cis-[Mn(en)_2Cl_2]$ is: $(en = NH_2CH_2CH_2NH_2)$

Which one of the following pairs of isomers and types of isomerism are correctly matched?
$(i).$ $[Co(NH_3)_5(NO_2)]Cl_2$ and $[Co(NH_3)_5(ONO)]Cl_2$ .... (Linkage)
$(ii).$ $[Cu(NH_3)_4][PtCl_4]$ and $[Pt(NH_3)_4][CuCl_4]$ .... (Coordination)
$(iii).$ $[PtCl_2(NH_3)_4]Br_2$ and $[PtBr_2(NH_3)_4]Cl_2$ .... (Ionization)
Select the correct answer using the codes given below.