D430 PA vs OA

Once again, I am posting about this course cause I am going insane. I have passed the pretest now 3 times, all well above passing, but I have failed the OA twice. I have made my own study guide and used the quizlet the CI provided and a quizlet I have found here. I understand the material, but I still have no clue why I am not understanding the OA. I am about to take my 3rd test retake, but thinking I should wait and attend the cohort on Thursday. Any advice for this test??