Which of the following complexes are homoleptic?
Homoleptic complexes are attached to only one kind of ligand. Here, in option (i)[Co(NH3)6]3+ and (iii)[Ni(CN)4]2– are bonded to only one ligand which is NH3 and CN- respectively so these two complexes are homoleptic.
Whereas, in options (ii) and (iv), there are two types of ligands are connected with Central Atom and thus these are not correct.
Thus, Options A and C are the correct answers.