Having just heard of yet another story of a student getting a drastically different grade out of an essay remark (she went from a B to an A+), I just wanted to remind you that you’re well within your rights to ask for a second opinion on any assessment work. By now you should have a pretty good idea of what constitutes a C, B, and A essay so if you get a shock grade without any clear indication of why, it’s a smart move to follow it up.
If you’ve checked your work against any assessment specifications or marking schedules you may have been given before submitting it, and still can’t find a reason for getting the mark you did, politely approach your marker to ask for a bit more feedback. Even if your grade doesn’t go up, you should get a much clearer idea of where you went wrong and some tips on what to do better next time. If you’ve approached the marker, and are still left with a mark that doesn’t make sense to you, take it to the head of the programme.