If a major at a college are filled to capacity, what is preferable for the college to do?

@profparent "Interesting that you don’t include the option:

D. Hire more faculty and run more sections of courses so that students can choose (and switch) majors with greater freedom."

I agree, and that is what the private schools often do as demand for majors shifts, but for some reason, the Public Universities seem to generally seem to have a lot of difficulty doing this for some reason.