Is 'Animal Farm' harder to yse than 'Brave New World' or "A Clockwork Orange'?

We have to do a project at school, where we yse 3 books. I've already chosen two but I'm struggling to choose another. Its between Animal Farm, Brave New World or Clockwork Orange. Its the first time I'm doing a project like this so I don't want it to be too hard. Which of these books would have the more substanse and would be easier?