Which among the following complexes does $NOT$ exhibit different geometrical isomers? [$M=$ metal ion and $A, B, C=$ ligands]

Which one of the following will be able to show $cis-trans$ isomerism?

The number of geometrical isomers of the complex $[Co(NO_2)_2(NH_3)_2]$ is

The magnetic moment of $Ni^{2+}$ in an aqueous solution is ......... $B.M.$

Which of the following complex compound$(s)$ is/are paramagnetic and low spin?
$(I) \, K_3[Fe(CN)_6] \quad (II) \, [Ni(CO)_4] \quad (III) \, [Cr(NH_3)_6]^{3+} \quad (IV) \, [Mn(CN)_6]^{4-}$
Choose the correct code:

Give an example of solvate isomerism.