When you lose enough points to reach 8350 (the limit is 8499), your rank will become D+ and you'll get this "achievement"
As a small recommendation I would say it's best to do this one and the E achievement the first time you are on the DOA server. You don't need that many losses to do both so it's very doable.
The reason for this is that you will get an option when you return the second time if you want to reset your rank. If you do you will start on the C rank with the same amount of points as the first time. So you will get both E and D ranks without any real penalties.