English Exam Essay Help

Hello, i have a english exam tommorow, and part 1 of the exam is an essay. The topic of the essay is acutally unknown to me but my teacher narrowed it down to two topics, theme and character in the novels/play The Adeventure of Huckleberry Finn, Catcher in the Rye, or a Midsummers Night Dream. You are supposed to pick one theme from the novels/play and state how that theme is present in the books. You also could pick a character from each book and compare/contrast the two characters. If anyone has any good ideas please let me know ASAP,

Thanks,