Concept:A ligand is neutral if it has no charge in its coordination compound form.Explanation:Ammine refers to NH3​, which is an uncharged molecule.Chloro is Cl−, an anionic ligand.Sulphato is SO42−​, an anionic ligand.Nitrito is NO2−​, an anionic ligand.Only ammine carries zero charge on the ligand.Answer:The neutral ligand is A. Ammine.