MAC is defined as follows in the Handbook of Information Security Management: With mandatory controls, only administrators and not owners of resources may make decisions that bear on or derive from policy. Only an administrator may change the category of a resource, and no one may grant a right of access that is explicitly forbidden in the access control policy.

A Synchronous token generates a one-time password that is only valid for a short
period of time. Once the password is used it is no longer valid, and it expires if not entered in the
acceptable time frame.
The following answers are incorrect:
Variable callback system. Although variable callback systems are more flexible than fixed callback
systems, the system assumes the identity of the individual unless two-factor authentication is also
implemented. By itself, this method might allow an attacker access as a trusted user.
Fixed callback system. Authentication provides assurance that someone or something is who or
what he/it is supposed to be. Callback systems authenticate a person, but anyone can pretend to
be that person. They are tied to a specific place and phone number, which can be spoofed by
implementing call-forwarding.
Combination of callback and Caller ID. The caller ID and callback functionality provides greater confidence and auditability of the caller's identity. By disconnecting and calling back only authorized phone numbers, the system has a greater confidence in the location of the call. However, unless combined with strong authentication, any individual at the location could obtain access.
The following reference(s) were/was used to create this question: Shon Harris AIO v3 p. 140, 548 ISC2 OIG 2007 p. 152-153, 126-127

The Differential Backup Method is additive because the time and tape space required for each night's backup grows during the week as it copies the day's changed files and the previous days' changed files up to the last full backup. Archive Bits
Unless you've done a lot of backups in your time you've probably never heard of an Archive Bit. An archive bit is, essentially, a tag that is attached to every file. In actuality, it is a binary digit that is set on or off in the file, but that's crummy technical jargon that doesn't really tell us anything. For the sake of our discussion, just think of it as the flag on a mail box. If the flag is up, it means the file has been changed. If it's down, then the file is unchanged.
Archive bits let the backup software know what needs to be backed up. The differential and incremental backup types rely on the archive bit to direct them. Backup Types Full or Normal The "Full" or "normal" backup type is the most standard. This is the backup type that you would use if you wanted to backup every file in a given folder or drive. It backs up everything you direct it to regardless of what the archive bit says. It also resets all archive bits (puts the flags down). Most backup software, including the built-in Windows backup software, lets you select down to the individual file that you want backed up. You can also choose to backup things like the "system state".
Incremental When you schedule an incremental backup, you are in essence instructing the software to only backup files that have been changed, or files that have their flag up. After the incremental backup of that file has occured, that flag will go back down. If you perform a normal backup on Monday, then an incremental backup on Wednesday, the only files that will be backed up are those that have changed since Monday. If on Thursday someone deletes a file by accident, in order to get it back you will have to restore the full backup from Monday, followed by the Incremental backup from Wednesday.
Differential Differential backups are similar to incremental backups in that they only backup files with their archive bit, or flag, up. However, when a differential backup occurs it does not reset those archive bits which means, if the following day, another differential backup occurs, it will back up that file again regardless of whether that file has been changed or not. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 69.
And: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 9: Disaster Recovery and Business continuity (pages 617-619). And: http://www.brighthub.com/computing/windows-platform/articles/24531.aspx

The correct answer is "The percentage of loss that a realized threat event would have on a specific asset". Answer "Adollar figure that is assigned to a single event" is an SLE,
"Anumber that represents the estimated frequency of the occurrence of
an expected threat" is an ARO, and "The annual expected financial loss to an organization from a threat" is an ALE.