Electrons in a paramagnetic compound are

Which of the following is correctly matched?

The spin-only magnetic moment of a divalent ion in aqueous solution (atomic number $29$) is ...... $BM.$

Identify the homoleptic complexes with an odd number of $d$ electrons in the central metal ion.
$(A) \ [FeO_4]^{2-}$
$(B) \ [Fe(CN)_6]^{3-}$
$(C) \ [Fe(CN)_5 NO]^{2-}$
$(D) \ [CoCl_4]^{2-}$
$(E) \ [Co(H_2O)_3 F_3]$
Choose the correct answer from the options given below $:$

If the magnetic moment of $[Ag(CN)_2]^{-1}$ is zero,then the number of unpaired electrons will be

Amongst $Ni(CO)_4$,$[Ni(CN)_4]^{2-}$ and $[NiCl_4]^{2-}$,which of the following statements is correct regarding their magnetic properties?