Why would an author choose to employ a flashback to interrupt the chronological order of a narrative? to make the story more interesting to provide background information on something important to allow the audience a break from the monotony of the normal story telling device to jump around and make a story confusing

I would have to go with B) provide background information on something important because in most books/tv shows the author/producer adds flashbacks to help readers remember what happened and to add more information on a character/ or something. Its not C) or D) because that's wrong and I don't think its A) because flashbacks usually don't make stuff MORE interesting so it has to be B) to provide background information on something important.