The correct response that best explains the effect of the dramatic irony in the passage for the reader is:
"The reader knows that the box contains the purse Nikka wanted, so the effect is to experience the humor and anticipation of the scene."
This response accurately captures the tension and excitement that builds as the reader is aware of the true contents of the box, while Nikka initially misunderstands it. The reader experiences both humor from Nikka's misconceptions and anticipation as she discovers the actual gift, leading to a satisfying conclusion.