I'm in the same boat as the OP. I am interested only in getting the easiest possible U.S. Diversity class. What does this class require? It seems intriguing.
Rent the textbook. You have to post 4 times/week on the discussion board and take a quiz (three attempts..best score counts). Exams are online and supposed to be closed book. I've put less than a half hour into each week this semester.