What do i say when my parents get mad at me for doing bad in school?

So i did really bad in school this year, i went down in a lot of things, and i failed my PAT's. My parents said that if i don't do good in school this last term, i can't go to Track and Field anymore. Track is something i LOVE. I really don't want to stop. They won't take "I did the best i could this year" or anything. WHAT DO I DO? please please help me