Actually I had some good luck with hiring people that have the minimum marks and huge amount of outside adjacent skills. One example is someone who was running a manufacturing operation on second shift and completing an engineering degree at the same time.
Not specifically the same but there's an adage, "C's get degrees". (I guess it's about how even if you got C's, you're still good enough to have a sheet of paper that even your class topper had?)
I always went with C is for cookie and that's good enough for me. Along with D for diploma.
But note, some schools require a C in prereqs to take further courses. And some schools may put you on academic probation/kick you out if your GPA falls below a C. So D for diploma is a sometimes grade.