I believe they look at your overall GPA. Doing well on the pre requisite classes can also help. You have to have at least a 3.25 or you would have to take the GRE. I am not sure exactly when they start accepting applications but you would have to call them to be very sure.
Like cdwcobra95 said, have a strong recommendation letter but they do actually take everything in consideration including your GPA, essay, whether you have most or all of the pre requisite taking and how well you do on the interview. And also try and apply as early as you can!
Wow.... no reply ha? well i'm not too sure about the grading scale but i know someone who goes there and says the grading scale is very high like 94% is a 'B'. I will be starting their MENP in july so i would find out more about it.