What is the value of the spin-only magnetic moment for $Cu^{2+}$ in $BM$?

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 complexes does not show optical isomerism?

For a tetrahedral complex $[MCl_{4}]^{2-}$,the spin-only magnetic moment is $3.83 \ BM$. The element $M$ is

Select the correct pair of complexes that exhibit the same type of isomerism:

Which complex possesses a facial $(fac)$ isomer?