Which of the following statements is not correct?

The pair$(s)$ of complexes wherein both exhibit tetrahedral geometry is(are):
Note: $py = \text{pyridine}$
Given: Atomic numbers of $Fe, Co, Ni$ and $Cu$ are $26, 27, 28$ and $29$,respectively.
$(A)$ $[FeCl_4]^-$ and $[Fe(CO)_4]^{2-}$
$(B)$ $[Co(CO)_4]^-$ and $[CoCl_4]^{2-}$
$(C)$ $[Ni(CO)_4]$ and $[Ni(CN)_4]^{2-}$
$(D)$ $[Cu(py)_4]^+$ and $[Cu(CN)_4]^{3-}$

$[Co(NH_3)_6]^{3+}$ and $[CoF_6]^{3-}$ are respectively known as:

The number of unpaired electrons in $Ni(CO)_4$ is ..........

Which of the following complexes is paramagnetic and an inner orbital complex?

The shape of $[Cu(NH_3)_4]^{2+}$ is square planar. The $Cu^{2+}$ ion in this complex is: