Final answer:
Iago advises Cassio to appeal to Desdemona for help in getting back into Othello's good graces in Act II of 'Othello'.
Step-by-step explanation:
In Othello Act II, Iago suggests to Cassio that he should seek Desdemona's intercession to regain his position. Iago convinces Cassio that Desdemona's influence on Othello is strong and that if she pleads his case, Othello is likely to forgive him and restore his rank. This counsel is part of Iago's grander scheme to manipulate the characters and further his own questionable agendas within the play.