∵ Has no unpaired electron, thus is diamagnetic.
∵ Has no unpaired electron, thus is diamagnetic. (c) [NiCl2(PPh3)2]
As it has weak ligands with two unpaired electrons, thus it will show paramagnetic nature. (d) [Co(en)3]3+
∵(en) is a strong field ligand, all the unpaired electrons (i.e. 4) will go for pairing and we have no unpaired electron in the complex. Hence, is diamagnetic ∴(c) is the correct option.