C in first quarter senior year

Your ED decision will be out before a semester grade is done. Is the quarter on your transcript?

Any way, one C and tons of As should not preclude you from continuing with an application strategy. It doesn’t mean you’ll get in - Columbia is very difficult to get into.

If you don’t get in, you’d never know the why - and I doubt it would be the one grade - if it’s even a part of the admission decision.

Good luck.