According to ISO/IEC 27000, information security is defined as the "preservation of confidentiality, integrity, and availability of information." This definition highlights the three core principles of information security:

Confidentialityensures that information is not disclosed to unauthorized individuals or systems.

Integrityensures the accuracy and completeness of information and its processing methods.

Availabilityensures that authorized users have access to information and associated assets when required.

This definition encompasses the protection of information in all forms and aligns with ISO/IEC 27005’s guidelines on managing information security risks. Therefore, option A is the correct answer. Options B and C are incorrect as they refer to more specific aspects or other areas of information management.