Final answer:
The Wife of Bath reveals that her last husband's violent act was a response to her ripping a page from his book, lending new complexity to the story and their relationship dynamics.
Step-by-step explanation:
The new detail that Chaucer's Wife of Bath adds to her story in her prologue is that the act of violence from her last husband occurred after she ripped a page out of his book in a moment of anger, suggesting that her own actions precipitated his abusive response.
In the context of the narrative, this addition is significant as it reframes the nature of the incident, providing insight into the contentious dynamics of their marriage and the provocations that led to the assault. This detail has the effect of complicating our perceptions of the characters and their relationship, illuminating the Wife of Bath's role in the conflict.