In other words, if you choose this course, you either choose the wrong teacher or you don't choose this course at all. If you choose the wrong teacher, it will be easy. You can directly find your teacher and coordinate with the teacher you choose. The point is that if so, you won't have an examination room for your exam. If you don't take courses at all, it will be difficult. I have encountered such a situation, and the final solution is to take the exam again. It depends on whether your counselor is responsible or not, and it depends on the academic affairs office. This is very difficult.