In order to prevent students from copying each other’s answers, and to make sure you hear the genuine opinion of each student, you can hide the replies from your students.
After you create a Discussion, click on it and scroll to the bottom of the page. You will see a box labeled “Tools”.
By clicking “Hide replies from students”, your students will be able to submit replies to the discussion topic, but will not be able to view the other student’s responses. You can go back and click “Show replies” at any time to make the replies visible to students again.