Availability is defined as which of the following?

• A. Ensuring timely and reliable access to and use of information
• B. Ensuring information is never altered
• C. Protecting against data exfiltration
• D. Managing user identities and access

Answer: (A)

Availability means ensuring that information and systems are accessible when needed by authorized users. It’s about uptime, performance, and reliable access, even in the face of hardware failures or outages, supported by practices like redundancy, backups, and disaster recovery. This is why the option describing timely and reliable access to and use of information best captures the concept. The other ideas refer to different security goals: keeping data unchanged points to integrity; preventing unauthorized data exfiltration relates to confidentiality; and managing who can log in covers identity and access management.