Amongst[ Ni (CO)4], [Ni (CN)4]2– and [NiCl4]2

4 1.[Ni(CO) ],Ni=0 8 2 2- 4 +2 8 2- 4 +2 8 Ni=[Ar]3d 4s 2.[Ni(CN) ] ,Ni=+2 Ni =[Ar]3d 3.[NiCl ] ,Ni=+2 Ni =[Ar]3d CO and CN- are strong filed ligands Hence, both the complexes are diamagnetic in nature whereas Cl- is a weak field ligand, Hence, this complex is paramagnetic. Hence, the correct answer is option (c)