Shuffle
If you set this option to "Yes", then the order of the subquestions is randomly shuffled each time a student starts an attempt at a quiz containing this question - provided that "Shuffle within questions" in the Quiz settings is set to "Yes".
The intention is simply to make it a little harder for students to copy from each other.
Discaimer: This project has been funded with support from the European Commission. The presentation reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.