Complex ions with different ligands have different colors because the ligands: Group of answer choices are different colors affect the energy levels of the lone-pair electrons on the metal have different energies for their bonding electrons affect the energy levels of the metal d orbitals have different energies for their lone-pair electrons

The correct answer is the second last statement, that is, it affects the energy levels of the metal d orbitals.

Explanation:

It is because of the d-d transition of electrons that the metal complexes exhibit color. When bonding of the ligands takes place with the transition metal ion, a repulsion results between the electrons in the d orbitals of the metal ion and the electrons found within the ligands. This increases the d orbitals' energy level.  

However, based on the alignment of the d orbitals in the space, all of the energies do not get elevated by the same level, it gets dissociate into two groups. This dissociation of the d-orbitals relies upon the ligand's strength. More amount of energy would be required to encourage an electron from the lower orbitals groups to the move towards the higher ones in case if the splitting is more.  

Greater energy is equivalent to shorter wavelengths in terms of the color of the light absorbed. The complex ions possessing different ligands show distinct kinds of colors as the energy levels of the d orbitals of the metal get affected by the ligands.