The spin-only magnetic moment value of the square planar complex $[Pt(NH_3)_2 Cl(NH_2 CH_3)] Cl$ is $B.M.$ (Nearest integer). (Given atomic number for $Pt = 78$)

List various types of isomerism possible for coordination compounds,giving an example of each.

The complexes given below show:

Which one of the following complexes will have four isomers?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The total number of geometrical isomers shown by $[Co(en)_2 Cl_2]^{+}$ complex ion is three.
Reason $R$: $[Co(en)_2 Cl_2]^{+}$ complex ion has an octahedral geometry.
In the light of the above statements,choose the most appropriate answer from the options given below:

Among the following complex ions,the one which shows geometrical isomerism will be