Which of the following concepts defines the requirement for data availability?

A.
Authentication to RADIUS

B.
Non-repudiation of email messages

C.
Disaster recovery planning

D.
Encryption of email messages

Explanation:
A disaster-recovery plan, or scheme, helps an organization respond effectively when a disaster occurs.
Disasters may include system failure, network failure, infrastructure failure, and natural disaster. The primary
emphasis of such a plan is reestablishing services and minimizing losses.