Final answer:
The frame of the Pardoner's tale is chiefly used to underline his greed and dishonesty, providing a moral lesson about irony and hypocrisy in figures of authority.
Step-by-step explanation:
The Pardoner's tale was enhanced by the frame primarily because it highlighted the greed and dishonesty of the Pardoner. This is part of the criticism of the era's religious figures, who would often exploit the faith and ignorance of the laity for personal gain. The Pardoner himself admits to using the tale to get money from those he preaches to, thereby reinforcing the moral lesson that irony and hypocrisy can be found amongst the seemingly pious.