Explanation/Reference:
Explanation:
With load balancing, often through clustering, each system takes a part of the processing load, and if one system fails there is an automatic failover to the other systems which continue to work. This guarantees a high availability of the service.
Incorrect Answers:
A: Systems backups only protects against data loss. It does not product a failure of server.
B: Electronic vaulting and remote journaling are transaction redundancy solutions. It protects the system by copying transaction information to a remote location. In case of server failure, the database can be restored, but it would require a rebuild of the database.
C: RAID protects against hard disk failures, but it does not protect against other type of server failures.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 1272

RADIUS is a protocol for carrying authentication, authorization, and configuration information between a Network Access Server, which desires to authenticate its links and a shared Authentication Server. RADIUS is a standard published in RFC2138 as mentioned above.

Explanation
Section: Security Operations

Explanation/Reference:
Explanation:
System sensing access control readers, also called transponders, recognize the presence of an approaching object within a specific area. This type of system does not require the user to swipe the card through the reader. The reader sends out interrogating signals and obtains the access code from the card without the user having to do anything.
Incorrect Answers:
A: A passive system sensing device contains no battery or power on the card, but senses the electromagnetic field transmitted by the reader and transmits at different frequencies using the power field of the reader. This device does not send an access code. Therefore, this answer is incorrect.
C: A swipe card requires the action from the user; the user has to swipe the card. Therefore, this answer is incorrect.
D: A magnetic card requires the action from the user; the user has to swipe the card. Therefore, this answer is incorrect.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 484 Krutz, Ronald L. and Russell Dean Vines, The CISSP and CAP Prep Guide: Mastering CISSP and CAP, Wiley Publishing, Indianapolis, 2007, p. 471