If enabled, then when students have finished attempting particular question, they will see a Redo question button. This allows them to attempt another version of the same question, without having to submit the entire quiz attempt and start another one. This option is mainly useful for practice quizzes.

This setting only affects questions (for example not Essay questions) and behaviours (for example Immediate feedback, or Interactive with multiple tries) where it is possible for student to finish the question before the attempt is submitted.