Agree with @collegemom3717. Don’t retake the ACT. You have to disclose all scores (so a possible lack of improvement would be a negative) and this is good enough that it won’t count against you.
Focus on getting all 5s in your APs and then prepping for the test and interview. Having some extra-curricular economics involvement might help also (internship, summer program, etc).
It’s going to be a very mathematically oriented course so the most relevant APs will be Calculus BC and Statistics. Most British candidates will have maths and further maths which cover some parts of AP Physics. If you haven’t done Calc BC in junior year then a conditional offer might result.