My advice, pick the one you find more interesting since you're going to be spending a good deal of time reading/writing about it.

You don't attend the University of Melbourne by any chance? I know they are running a subject with that name. Personally, I like the first question. It allows you to take a stance as well as decide what success actually means. Many rebellions/revisions in South America were "successful" in the sense that they succeeded in overturning the government but the ideals behind the revolution/rebellion were often never realised and the new government turned into a dictatorship that was seldom pleasant for the people living under it. Hardly what I would call successful. I can think of a few examples off the top of my head but if you've been paying attention to your course I'm sure you'll be able to do that as well.