The pair(s) of complexes wherein both exhibit tetrahedral geometry is(are)
(Note: py = 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 $$[Cu(CN)_4]^{3-}$$