Does the highest mark count (AQA Physics)?

Hi,

Basically this year I have done a lot on Mechanics (M1 and M2) and feel that I can get a better mark in AQA Physics Unit 2. If I do I have 2 weeks to revise do you think that will be a risk? I mean I looked one of the papers again, the mechanics section was straight forward I just to to recall all the theory. Anyway, in a bad case, if I get a lower grade than before would my highest or the most recent count? Teachers say it's the highest although they you the word 'should' :/

Cheers

It would be the highest mark, but can you still sign up to resit the paper this close to the exam?