Is the D a grade for the first quarter or first semester? For USC on the Common App you don’t have to include senior year grades, just freshman through junior years. There is an Additional Info section where you can address a bad grade, but it doesn’t sound like you should because they won’t see it unless they get your mid year report. And, at that time, you can send a note to your admission counselor explaining it if you don’t pull it up in time for the mid year (if it’s a quarter grade). If your application is strong (ACT/SAT, gpa, recs, etc) they may not even ask for your mid year report, but you should find out if your school is going to automatically send one.