I'm going to say B, because she felt to smart for them, office classes tend to be advanced.
Thesis definition: a statement or theory that is put forward as a premise to be maintained or proved
So,
Without having a recognizable thesis, your reader will not fully understand what point you are trying to get across. Furthermore, your writing will seem to have no meaning or purpose, and will not inform the reader. To clarify, if you do not have a recognizable thesis, your writing would be pointless.
