So I was admitted to the McGill faculty of arts and my acceptance letter said that "my offer of admission will remain valid provided that you maintain your current level of academic achievement and obtain your high school diploma." However, this semester I am doing really bad in my math class. My grade dropped from a B- to a D+. Math isn't a prerequisite for the Arts program and I am not required to take math at McGill. Should I be worried that they will revoke my offer? Does McGill ofter rescind on offers of admission?