How Do I Restrict Access To Quizzes For Past Students?
Go to your Quizzes tab within the desired course.
Click on the tab to the right of the desired quiz and click on Edit.
Once in Edit Quiz mode, click on the fifth tab entitled Submission Views.
Once you get to this window you will see there are two types of views: Default and Additional. The default controls what the student can see after they attempt the quiz. If a teacher wants to restrict the students' view up to a certain date, they can add an additional view that will change the view on a certain date. For a quiz from an old course that you want to hide, you should delete any additional views. Next click on the blue link: Default View.
The best way to restrict a students view of the answers is to select No under the Show Questions? area. Click on Save to keep the changes. Make sure to delete the additional views and set the default view to No on any Quiz that you do not want old students to access.