How many optical isomers are possible for the complex $[Pt(NH_3)_2(CN)_2]$?

The two compounds pentaamminesulphatocobalt $(III)$ bromide and pentaamminesulphatocobalt $(III)$ chloride represent:

Among the following complexes $(K-P)$,
$K_3[Fe(CN)_6]$ $(K)$,$[Co(NH_3)_6]Cl_3$ $(L)$,$Na_3[Co(ox)_3]$ $(M)$,$[Ni(H_2O)_6]Cl_2$ $(N)$,$K_2[Pt(CN)_4]$ $(O)$ and $[Zn(H_2O)_6](NO_3)_2$ $(P)$,the diamagnetic complexes are

Which of the following pairs represent linkage isomers?

$[Fe(NO_2)_3Cl_3]$ and $[Fe(ONO)_3Cl_3]$ show:

The correct match of the complexes with their structure and magnetic property is:

Complex	Structure and magnetic property
$i$. $NiCl_4^{2-}$	$p$. tetrahedral and diamagnetic
$ii$. $Ni(CO)_4$	$q$. tetrahedral and paramagnetic
$iii$. $PtCl_4^{2-}$	$r$. square planar and diamagnetic
$iv$. $Ni(CN)_4^{2-}$	$s$. square planar and paramagnetic