The incremental backup method usually resets the archive bit on the files after they have been backed up.
An Incremental Backup will backup all the files that have changed since the last Full Backup (the first time it is run after a full backup was previously completed) or after an Incremental Backup (for the second backup and subsequent backups) and sets the archive bit to 0. This type of backup take less time during the backup phase but it will take more time to restore.
The other answers are all incorrect choices.
The following backup types also exists: Full Backup -All data are backed up. The archive bit is cleared, which means that it is set to 0. Differential Backup -Backup the files that have been modified since the last Full Backup. The archive bit does not change. Take more time while the backup phase is performed and take less time to restore.
Reference(s) used for this question: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69.