Ans.
When Duke Orsino arrived before Olivia's house with Cesario, the officers of justice brought their prisoner, Antonio, before the Duke. Seeing Cesario, Antonio thought him to be Sebastian and charged him of ingratitude. At that time Olivia came out of her house and demanded Cesario as her husband. Hearing it, Orsino accused Cesario with ingratitude and threatened him with instant death. Just then another Cesario appeared and he declared Olivia as his wife. The new Cesario was actually Sebastian, the real husband of Olivia and the brother of Viola. Everybody looked at the two identical twins. Viola now acknowledged that she was a lady in disguise of Cesario. Thus all confusion was cleared up.