http://www.dictionary.com

Come on – it’s multiple choice. How much help did you really need? Or is it just that you don’t feel like learning this yourself and you want someone else to do the work for you?

None of the choices you off is defined by its length, or the narrowness of its focus. All four of the examples you name could be the answer.

A. Novel–Moby Dick, a reflection on the whaling industry in the nineteenth century. And long!

B. Essay–Virtually any nonfiction book at your local bookstore.

C. Angela’s Ashes–Frank McCourt’s memoir that is a book-length account of himself.

D. Poem–Dante’s “The Divine Comedy,”–long enough to keep you busy for the rest of your life!

I see this is your first question at Yahoo answers. Welcome to the club!