In oedipus the king, how does the setting most affect the development of the plot?

by downplaying the ironic importance of the palace of thebes while oedipus remains unaware of his true identity
by utilizing the chorus to clarify that oedipus’s central conflict is affected by an annual oracle from the gods
by employing foreshadowing techniques to illuminate the timing of oedipus’s self-revelation
by retelling the familiar story of the hero, oedipus, but changing the location of the tale to provide objective distance