Oh, and as @MikeSauce said, if you call them and ask, they’ll tell you to take the C (and as my quote from the website says, that might be the only option since it’s a pre-req). I have a few C-'s that were 10 years old and while they weren’t pre-reqs, when I went into Haas several months ago and asked if I should retake them, they said to not even worry about it. Regardless, I’m retaking them as three C-'s that I can now easily get A’s in would kill my GPA, but their school of thought was that it was 10 years ago and my overall application would show that’s not who I am anymore, holistic, blah blah blah.