A government agency classifies data based on sensitivity levels and ensures that only personnel with the appropriate clearance can access classified documents. Which CIA principle does this security control support?

Availability refers to ensuring that information and resources are accessible to authorized users when needed. While important for operational efficiency, this principle does not specifically address the control of who can access sensitive information, which is the focus of the security control described in the question.

Integrity involves maintaining the accuracy and consistency of data over its lifecycle, ensuring that information remains unaltered and reliable. The principle of integrity does not directly relate to access restrictions or the confidentiality of classified documents, as it is more concerned with data correctness rather than who can view it.

Authentication is the process of verifying the identity of a user, system, or entity before granting access to resources. While it plays a role in securing information, it is not the principle that specifically addresses the protection of sensitive data through access controls. Authentication is a means to achieve confidentiality but is not the principle itself.