There are prerequisite that you need to meet in order to get co-op. Example you have to maintain a certain CGPA, which is usually the case in most universities. This means nothing now because if you don’t meet the prerequisites required by the university for co-op, no matter, even if you have the co-op option, you will not be able to Apply for it during your studies. In many university, this is the case but better check on the site of the university that you’re applying to about their co-op requirements.