Why does plato try to prove their are three parts of the human soul?

Explanation:

Plato argues that three are three parts of the soul namely as rational, appetitive and spirited. These three parts have just ranked the community in three divisions. The personal justice involves the maintaining of three parts in the proper balance where the reason rule whereas appetitive obeys. According to Plato, the appetitive part is the part of the soul is one that accounts for desires in people. It accounts for effortless craving required to stay alive like hunger, thirst, and for pointless craving like the desire to overfeed. This desire should be limited to another part of the soul. The rational soul, is the thinking elements in every human being,  which decided that what is factual and what is untrue and intelligently make a sensible decision.

answer; (d) anthropology;