Links
This is the College Board homepage.
This is the main page for the 2D Design course. You can find the course description, sample portfolios, and scoring rubrics here.
This is the main page for the AP Drawing course. Here you can find the course description, sample portfolios, and scoring rubrics.
This is just a generic list of successful sustained investigation ideas. This is not an exhaustive list and you should not just pick something from this list. The success or failure of your sustained investigation will be based more on your skill, exploration, and experimentation in presenting your works to the AP readers. There is no "one size fits all" approach to the AP Studio Art exams.