Which of the following server contingency solutions offers the highest availability? 

Answer options:

A. System backups
B. Electronic vaulting/remote journaling
C. Redundant arrays of independent disks (RAID)
D. Load balancing/disk replication

D

Of the offered technologies, load balancing/disk replication offers the highest availability, measured in terms of minutes of lost data or server downtime. A Network-Attached Storage (NAS) or a Storage Area Network (SAN) solution combined with virtualization would offer an even higher availability. Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 49).