Why answer B

Hi @jharbour, Thanks for the question! We’re being asked for a flaw here. What’s the flaw in the original stimulus? That we can’t assume that the night security guard is telling the truth! They may have been lying. It’s possibly that they’re actually the ones who stole the portrait, who knows? So we want an answer choice in which we have reason to doubt the narrator, in which there’s an incentive to lie. And that’s replicated in (B). Hope this helps! Feel free to ask any other questions that you might have.