Companycom has been performing scheduled backups of their data to tape using "tar" in a script for over one year with no problems. Recently, the tar command is returning a non zero return code during the backup phase, causing the script to fail. What is the primary cause of this problem?（）

• A、The files have grown to over eight gigabytes in size
• B、The file systems are corrupt, and fsck should be run
• C、The tape block size has been changed from the default
• D、The user’s limit has been changed to less than eight gigabytes