Which Ethics and GIPS standards have been most tested?

Any insight would be helpful as I’m trying to re-read certain standards more often as we approach test day.

The reason I’m asking is because I failed L3 before and scored terribly in Ethics. However, I did read the topic twice and did the EOCs and mock questions. Yet during the exam I felt that at best I had to guess most answers whereas during the mocks I was quiet confident.