Restricting Access Based on Activity Completion

First, enable completion tracking in your course (this needs to be done only once):

Second, enable completing tracking for each assignment:

1) Create an assignment'

2) Open the "Activity completion" options;

3) Set "Completion tracking" to "Show activity as complete when conditions are met."

4) Enable "Student must view..." and "Student must submit...."

5) Add the answer sheet. I always recommend linking it to a page, but any resource will work.

6) Open the ?Restrict access? options.

Click ?Add restriction.?

7) Click ?Activity completion.?

8) Choose the activity and ?must be marked as complete.?

9) Save.