It depends on whether you have time. You'd better study the outline thoroughly before entering the exam, so that reading will get twice the result with half the effort, and choosing to read will not save time and energy. The advantage of applying for a class is that the teacher gives some points and reduces unnecessary points. Teachers are good or bad, and some are just classes that college students are looking for casually. Therefore, if you want to sign up for classes, you'd better choose a reputable one, and the pass rate is relatively high. You can check it online yourself.