U-Michigan "which activity" essay

Hi,

I’m filling out the U-Michigan writing section of the common app right now and I’m struggling with the first question (If you could only do one of the activities you have listed in the Activities section of your Common Application, which one would you keep doing? Why?). Actually feel pretty good about the other two.
Any thoughts on how to tackle this? The problem is that most of the activities I listed in the common app were very specific to my time in high school (e.g. Cross Country captain, Philosophy club president) and aren’t really relevant to my current situation, that is I’m not pursuing those particular activities at the moment. How should I extrapolate something personal and effective as an essay for this question in light of that?
Thanks!