Which statement about the control of combinations is true?

The statement that combinations must be safeguarded according to material classification is accurate because it underscores the necessity of protecting sensitive information based on its classification level. In security operations, different materials—such as confidential or classified information—require distinct handling and protection protocols to mitigate the risk of unauthorized access.

Safeguarding combinations according to material classification ensures that only authorized personnel can access critical data or areas, which is fundamental to maintaining the integrity of security practices in any organization. This approach aligns with broader security principles that emphasize the protection of sensitive information to prevent potential breaches or misuse.

The other options present different perspectives that do not align with established security practices regarding combination management. Sharing combinations with all staff members poses a significant security risk, as it could lead to unauthorized access. Not updating combinations regularly increases vulnerability, allowing individuals who might know the old combinations to retain access even when they should not. Lastly, suggesting that combinations are only relevant for entrance doors limits the understanding of their importance, as combinations can be required for various secure locations or systems beyond just physical entrances.