In case of octahedral compex, if the `e_(g)` orbitals `(d_(x^(2) - y^(2)) " and " d_(z^(2)))` are asymmetricaaly filled, their degeneracy is destroyed and the ligands approaching along `+Z` and `-Z` directions experiences different amount of repulsions than the ligands approaching along the `+X, -X, +Y " and " -Y` directions. As a result, the symmetrical nature of such complexes is lost and either elongation or compression along Z-axis taken place. Answer the following three questions based on the above situation.
Select the coorect statement.
A. `[Ni (CN)_(4)]^(2-)` is tetrahedral
B. `[Ni (CN)_(4)]^(2-)` is square planar
C. `[Cu (CN)_(4)]^(3-)` is square planar
D. `[Co (CN)_(4)]^(2-)` is tetrahedral