Should I do pass/fail for a B in a hard class?

I’m a business major and I got a B in a notoriously tough class at my school, so idealistically people keep saying a B is good and I don’t need to do pass/fail. However, it will lower my GPA since I have all A and A-s, and I doubt law schools care if it was a hard class at a hard school or not. The only thing I am worried about is if I do pass/fail, they might think I got a C- (the lowest to pass) instead of a B. What should I do?