Final answer:
Claudio, in his penance, agrees to marry the supposed cousin of his deceased lover as a form of atonement for his wrongful accusations that he believed led to her death.
Step-by-step explanation:
Believing his wrongful accusations have led to the death of his beloved, Claudio agrees to undergo penance as a form of atonement. This act of contrition involves several steps, including publicly admitting his error and mourning for Hero. However, one of the significant actions Claudio commits to as part of his penance is to marry another woman, who is presented to him as the cousin of his deceased lover, albeit under the guise of this being a sense of duty to her family. Ultimately, this situation resolves when it is revealed that the woman he agrees to marry is, in fact, Hero herself, who was not actually dead. This dramatic turn is a hallmark of the misunderstandings and resolutions that are common in the works of William Shakespeare, particularly in the play 'Much Ado About Nothing'.