Wow, tough one...would anybody like to discuss, after all that is how we will learn to get this correct on the real exam.
I knew the word "for" had to be used, as they were called renegade "for" their decision, or "for" deciding. So that brings us to A,B, and C.
I didn't like B, because it uses "the" decision, rather than "its" decision. After all, it was the school that made the decision, so we need an "its" to link that ownership. Now we have A and C.
In A, I personally didn't like the use of "at its 1833 founding". Although now that I read it, that seems to be active, while choice C is passive - and active is preferred when all else is equal.