PhD student with C grade in a core course

[PKGTA]

Good afternoon everyone. I am a 2nd year PhD student in Sociology. I was about to be ABD after Spring 22, but something bad has happened.

I was taking my last core course which is a purely theory-based one. I was also doing the usual graduate school stuff of teaching classes, trying to put together a committee, trying to show some progress on the PhD dissertation front; etc. There were other personal issues related to the pandemic. So, I was extremely burnt out at this point and the course was being taught by one of the oldest professors I have ever met. The material was dense and boring. In my frazzled state I did my best, but even though I did fully complete the requirements, he gave me a 'C'. This is the first 'C' I have ever received and by ever I mean 'ever', not just in grad school.

I am currently safe as a far as being kicked out of the program is concerned. I have the required GPA and all of my other grades are fine. However, what should I do now? Should I email the professor? My graduate advisor? What should I say and do? I know I would need to take this course again when it returns in about two years which in itself is making me upset, but what else should I do now? I am feeling very lost.

[Dreams]

Perhaps go to the professor's office hours to learn more about where he perceived your knowledge gaps to be and focus on remedying that for next time you take the class.  And approach it from an inquisitive standpoint vs a confrontational one to let the professor know you are really trying to give your best for the program.  Otherwise, just relax, these things do happen.