What types of markings appear on all derivatively classified documents?

The correct answer focuses on the specific requirements for markings on derivatively classified documents, which are those that incorporate or base their classification on existing classified information. These documents must include portion markings to indicate which parts of the document are classified or unclassified. Additionally, they must include "Classified By" and "Derived From" markings.

"Classified By" identifies the original classification authority responsible for the information, providing transparency about who classified the material. "Derived From" indicates the source of the original classification, highlighting the document's dependence on previously classified sources for its classification status. The inclusion of these markings ensures proper handling, dissemination, and understanding of the classified content within the document.

The other options do not fully capture the required elements of derivatively classified documents. For instance, the inclusion of only the classification level does not provide enough detail about the classification's source or structure. Similarly, while the date of classification and authority is important in some contexts, it is not comprehensive regarding the necessary markings for identifiability and accountability in derivatively classified materials. Lastly, a summary of content and intended audience are not standard markings required by classification policies for such documents.