What type of marking is used for information that necessitates special access under a SAP?

The correct choice, referring to the type of marking used for information that necessitates special access under a Special Access Program (SAP), is the Special Access Program banner marking. This marking is specifically designed to indicate that the information contained within requires a higher level of protection and access control beyond that of standard classified information.

The SAP banner marking serves as a clear visual cue that the information is part of a program that has stringent access requirements, ensuring that only individuals who possess the necessary clearances and need-to-know are granted access to this sensitive material. This helps to maintain the integrity and security of the information, which is essential for protecting national security interests.

While other answer choices refer to methods of classification and marking, they do not specifically address the unique access controls required for Special Access Programs. Access Level Markings, for example, denote different sensitivity tiers but do not encapsulate the exclusive and controlled nature of SAPs. Similarly, Security Classification Guides provide direction on classification levels but do not offer a marking specific to special access, and Restricted Access Indication implies limited access without the specific legal framework that governs SAPs. Thus, the Special Access Program banner marking is the most accurate and relevant choice for this context.