Which of the following is a requirement for handling classified information?

Handling classified information requires that it should be stored in a secure location to prevent unauthorized access. This principle is foundational to safeguarding sensitive information, ensuring that only authorized personnel can access, manage, or transmit classified materials. A secure location typically has protective measures in place, such as controlled access, surveillance, and an environment that guards against physical and digital threats.

This requirement reflects compliance with laws and policies governing national security and information protection. Storing classified materials properly mitigates risks such as espionage, leaks, or accidental disclosures, thus maintaining the integrity of national security interests.

In contrast, the other options do not align with established requirements for handling classified information. For example, there is no mandate that classified info must always be in digital format, nor is regular monthly review a general requirement. Furthermore, handling procedures are critical and cannot be disregarded—they provide necessary guidance on the proper methods for dealing with classified information.