The best response is: A reader might know things that the characters do not.
This creates suspense because the reader is aware of potential dangers or plot twists that the characters are oblivious to, leading to an atmosphere of tension as the reader anticipates how the characters will react when they eventually discover this information. Additionally, this can also create humor if the characters are making light-hearted or foolish choices based on their ignorance, while the reader knows the reality of the situation, leading to dramatic irony.