Refer to the Exhibit. You are designing a new backup and recovery solution. You have determined that a disk- aware backup-to-disk solution will be used as the primary destination for backups. Once…

Refer to the Exhibit. You are designing a new backup and recovery solution. You have determined that a disk- aware backup-to-disk solution will be used as the primary destination for backups. Once backups reach a specific retention period on disk, they will be moved to tape. To satisfy 90% of the e-mail restore requests from disk, what is the minimum required retention period?