I would choose English lit and history, for sure, because essay subjects are looked really favorably for law courses. They're also facilitating, which is great. For a third option you could pick whatever you want, really. If you want to keep your options a bit broad, maybe go for maths? Otherwise, economics looks like a really good choice there. I wouldn't necessarily go for biology because it isn't really relevant to law, and it looks like it would be a lot of hard work, plus since you definitely want to do history and english, then you already have your two facilitating subjects.
Cheers