Final answer:
Iago diverts attention towards Bianca while tending to the wounded Cassio, falsely implicating her in his scheming.
Step-by-step explanation:
While tending to the wounded Cassio, Iago repeatedly tries to divert attention (and therefore guilt) toward Bianca. Iago manipulates the situation to suggest that Bianca is involved in Cassio's misfortunes, despite knowing it's his own machinations that led to the outcome. He does this as part of his larger scheme to discredit Cassio and secure his own advancement while covering up his duplicitous actions.