1.
Are you interested in these subjects? Look through the exam specs, watch some videos and reflect on your GCSE experience if you took them
2.
Do these subjects allow you to do the career or degree youre aiming for in the future? Maybe research some careers or degrees. Uniguide is a great place to look for uni requirements and browse different course ideas
3.
Are you good at these subjects? Think about how easy it was to do well at the them at GCSE, how you revised, what grades you got etc. if you didnt take any of these at gcse think about similar subjects. Maybe look at some past papers and see if the questions align with your strengths