ionisation isomerism
coordinate isomerism
geometrical isomerism
linkage isomerism
A + AgNO3 → (x) white
White precipitate is AgCl (x).
This shows that Cl- is present as a counter ion in A.
B + BaCl2 → (y) white
White precipitate is BaSO4 (y).
This shows that SO42- is present as a counter ion in B.
A and B are ionisation isomers because they differ in the ions outside the coordination sphere. Therefore, the type of isomerism exhibited by the complex is ionization isomerism.