Final year project choice

Hi, I am on my final year in mechanical engineering and I have a couple of projects that I am considering and I am confused on which one to take and how to select a final year project.

I hace one project which is quite difficult and complex. It is related to plazma technology and renewable energy and it involves design, research, building a lab scale plasma reactor, and modelling

And the other projects are less difficult such as disk breaking finite element analysis , study of a gas turbine

So how should I select my FYP? I would really appreciate any advice