Which schedule can be configured as a synthetic backup in addition to the full backup...

The correct answer is Cumulative incremental backup. In NetBackup policy schedule configuration, the Synthetic backup schedule attribute is not limited only to a Full schedule. Cohesity documentation states that the Synthetic backup attribute allows a backup image to be assembled from prior backup images and that “a synthetic backup may be a synthetic full or a synthetic cumulative incremental backup.” This directly identifies cumulative incremental as the additional schedule type that can be configured as synthetic. Differential incremental backups are normally used as component images that feed the synthetic operation; they capture changed data and are later consolidated, but they are not the synthetic schedule type in this question. User archive and Vault catalog backup schedules are unrelated to synthetic backup image construction. Cohesity also explains that a synthetic cumulative incremental backup is produced by consolidating component images, including differential incremental backups taken since the last cumulative backup and, when available, the last cumulative incremental backup. Therefore, besides Full, the schedule type that supports synthetic configuration is Cumulative incremental backup. References/topics: Synthetic backup schedule attribute, Synthetic cumulative incremental backups, and Schedules required for synthetic backups.