Where does Sophocles accomplish catharsis in Oedipus Rex?

Theis in
the ending or resolution to the drama.  It is here where the "cleansing" of both
audience andis present.  When Act IV is concluded, bothand the audience are both horrified at
the news of the shepherd.  It is at this moment, where much in way of filth has reached its
zenith.  Oedipus' pride, his boasting of free will, and his absolute confidence that he can
overcome the power of divined fate are illusions whose collision presens itself at the end of
Act IV, and whose shards open Act V. 's suicide, at "being married to her son and thus had
given birth to his children,"...