Is Carleton's Norman Paterson School of International Affairs difficult to get into?

[Jar of Inspiration]

I really, really want to get accepted next year for the M.A. program. I'm not an academically brilliant student. My average is a B-B+. The website doesn't make it clear what else they look for. I am just starting my fourth year now and I will do whatever it takes this year to make sure I get in next September. Is it difficult, and what can I do to increase my chances?