Which of the following will be able to show geometrical isomerism?

The magnetic moment of a transition metal ion is $3.87 \, B.M$. How many unpaired electrons are present in it?

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: $(en = NH_2CH_2CH_2NH_2)$

The spin-only magnetic moment value of $M^{n+}$ ion formed among $Ni$, $Zn$, $Mn$, and $Cu$ that has the least enthalpy of atomisation is $........$ (in nearest integer). Here $n$ is equal to the number of diamagnetic complexes among $K_2[NiCl_4]$, $[Zn(H_2O)_6]Cl_2$, $K_3[Mn(CN)_6]$, and $[Cu(PPh_3)_3I]$.

Which one of the following complexes exhibits chirality?

The number of geometrical isomers found in the metal complexes $[PtCl_2(NH_3)_2]$,$[Ni(CO)_4]$,$[Ru(H_2O)_3Cl_3]$ and $[CoCl_2(NH_3)_4]^+$ respectively,are :