The correct response that accurately contrasts the Proterozoic and Phanerozoic Eons is:
Proterozoic eon animals were single cells or more primitive, and the Earth was just forming. Phanerozoic eon animals were multicellular and complex, Earth had formed continents, and continental drift was beginning to happen.
This response reflects the characteristic life forms of each eon, as well as the geological developments that occurred during these time periods. The Proterozoic eon is notable for early single-celled organisms and the buildup of atmospheric oxygen, while the Phanerozoic eon is marked by the rapid diversification of complex multicellular life and significant continental movements.