Business Economics admission might be rescinded, what can I do?

So all was well until I took my final in my Calc 2 class. Pre-final I was at an 85.85% and I bombed it. I’ve done the math and I would have needed at least a 70% on it to keep my grade at the required B for transfer. I am pretty certain that I am now at a C in that class but won’t know for sure until tomorrow afternoon. I informed my Calc teacher of how my future depends heavily on this test but I honestly don’t think he cares or will make any arrangements to try and boost my grade to what I need, despite seeming like a nice guy. Which I can hope all I want, but I’m not expecting it.

I contacted an adviser through the admissions portal and she said that should I get a C my admission status would be “carefully reviewed” and that I may be offered admission into another major. But she told me even that offer is not certain. She said to try and think of a major in the same School of Social Sciences to hopefully eventually change major, should I attend UCI this Fall.
I guess my question to all of you is what is my likely hood that I could be admitted into a different major, and have you ever heard of teachers being generous enough to not count something like this against them. Also if I eventually plan to change to Business Economics which major should I take if Econ/Quantitive Econ/ and Bus Econ are out of the question?