@chuchdaguch certainly, these sorts of things are worrying, and I, like you, would be worried if it were me. However, you have a 3.7. You have that MIT link. I think you will do OK. There are going to be a lot of students that just don’t bring their best game or aren’t cut out for Econ. Some are still sophomores.
Over the years, having looked at some of the prof rating sites, such as Rate My Professor and Bruinwalk (UCLA), I am still continually shocked at the number of students who don’t go to class. (UCLA especially.)
There are many reasons a student might not get a C. FWIW, the fact that you’re pro-actively concerned makes me think you won’t be one of them.