Which of the following statements is incorrect?

Dimethyl glyoxime forms a square planar complex with $Ni^{2+}$. This complex should be

In the extraction of silver,zinc metal is used as a reducing agent. What is the molecular structure of the zinc complex formed in this reaction?

Which of the following complex ions has $0$ $d$-electrons in the central metal atom? (Atomic numbers: $Cr = 24, Mn = 25, Fe = 26, Co = 27$)

Which one of the following is square planar in structure and has diamagnetic property?

Nickel $(Z = 28)$ combines with a uninegative monodentate ligand $X^{-}$ to form a paramagnetic complex $[NiX_4]^{-2}.$ The number of unpaired electron$(s)$ in the nickel and geometry of this complex ion are,respectively $:$