Final answer:
The original question does not pertain to an established event within Greek mythology; therefore, the Tutor could not have overheard anything related to the options provided, and the question may be based on a scenario outside of classical texts.
Step-by-step explanation:
The comes from the context of Greek mythology, specifically relating to the characters of Jason and Medea. While it doesn't exactly mention the story involving Oedipus, there is a similarity in that both stories involve the use of knowledge that comes to characters in unexpected ways. However, in the context of the original question, the Tutor does not overhear any of the options presented (a) Jason's betrayal, (b) Medea's plan, (c) political gossip, or (d) royal decree), in the park since this situation is not part of the established myths involving Jason and Medea, nor connected to the events in the drama involving Oedipus.