Which of the following complexes possesses a meridional $(mer)$ isomer?

An octahedral complex having molecular composition $Co \cdot 5NH_3 \cdot Cl \cdot SO_4$ has two isomers $A$ and $B$. The solution of $A$ gives a white precipitate with $AgNO_3$ solution and the solution of $B$ gives a white precipitate with $BaCl_2$ solution. The type of isomerism exhibited by the complex is,

Which of the following pairs of complexes are coordination isomers?

Explain different types of structural isomerism in coordination compounds.

In which of the following complex species,$\Delta_0 > P$ (pairing energy) with magnetic moment $\sqrt{3} \ B.M.$?

Which of the following ligands can show linkage isomerism?