If you really want to keep most options open Chem and probably Biology would do that. As your note interested in them you can basically rule out most life science courses.
It depends what you are interested in for the future. Just having Maths will open some forms of engineering, computer science, economics, accountancy and business course. Physics will help with some engineering courses. A humanities course like English or history would help towards tings like Law or Politics as would something like Politics Further Maths would help towards Maths university courses.
It is impossible to keep all options open but you need to follow courses that you will enjoy. You appear to have already ruled out 2 life science A levels. Imagine if you were compelled to take them how fed up you would be. That should tell you how important it is to subjects you will enjoy.