What does the term "marking" involve concerning classified information?

The correct answer focuses on marking as the process of applying appropriate labels to classified information that indicate its classification level and the specific handling requirements associated with it. This is a critical step in ensuring that anyone who comes into contact with the information understands its sensitivity and the risks involved in its handling.

Marking provides clear indications of how the information should be treated, which helps to protect it from unauthorized access and to ensure compliance with federal regulations. It specifies the classification level (such as Confidential, Secret, or Top Secret) and often includes additional guidance on dissemination and storage, thereby supporting the overall security framework for handling sensitive information.

While sorting documents, removing confidential information, and digital archiving are all important aspects of information management, they do not pertain specifically to the marking process defined in the context of classified information protection. Marking is exclusively about clearly identifying and labeling the information to inform users of its classification and associated handling protocols.