it's not really possible to guarantee 100 in an essay-based subject. you can basically guarantee full marks in crime mc, arguably human rights short response, but you would need to be adequately prepared for every single permutation of essay question in each of the two electives, and then also get lucky with your marker, which is far from a guarantee. it doesn't take much for an essay deserving 25/25 to be dropped down to a 23/25 because of the marker having a nitpick according to their personal preference, or recognising that it's a good essay, but some points fly over their heads or don't align with their view of what is correct on the evidence.