What is one key consideration when classifying new material derived from existing classified information?

The correct answer highlights the importance of adhering to the classification markings of the source material when classifying new material that is derived from existing classified information. This requirement is in place to ensure consistency and to maintain the integrity of the classification system. By following the source's classification markings, the derived material accurately reflects the sensitivity and context of the information.

When new documents are created from classified sources, they should carry over the existing classification markings, which indicate the level of sensitivity and the reasons behind the classification. This is essential to protect national security and ensure that users of the information understand its classified status.

Other options may suggest different approaches, but they do not align with the foundational principle of derivative classification, which is to maintain the original classification decisions and markings to prevent unauthorized disclosure of potentially sensitive information.