Solution:
\[\left( d \right)\text{ }\left( A\text{ }\to 4 \right),\text{ }\left( B\to \text{ }1 \right),\text{ }\left( C\text{ }\to 2 \right),\text{ }\left( D\text{ }\to 3 \right)\]
Isomerism in coordination compound is chosen by kind of ligands and calculation of coordination and game plan of ligands.