Should I do an EP related to degree choices or what I would enjoy more?

I'm studying maths, further maths, physics and chemistry at the moment (I'm in year 12). My school makes everyone do the EPQ so it's compulsory. I'm unsure of whether to do something related to science (physics in particular)/ engineering as that is what I intend to study at uni or whether I should do something unrelated to my subjects but I would enjoy a lot more e.g. something to do with learning a language as I love learning languages but I didn't decide to continue on with it to A level so this might be a good way for me to keep doing what I love while getting a qualification out of it?

But then again, it might be better to choose to do something closely related to my subject choices but I don't know. Any advice?