I'm sure I'll catch flak for this, but to help the OP out, you may not have to take it over again (at least if you're not an econ major).
The rule about requiring C's only applies to courses that are an immediate pre-req for another course.
For example, if you got a D in ECON 2010, you would not be allowed to take 2035. But because 2035 is the last ECON course in that succession, you would not be required to have a C, only a D (which is technically a passing grade).
Does that make sense?
I know this was true for Finance majors about 4 years ago (possibly because I experienced it firsthand with the exact same class
Let me know if you have any questions.