In accordance with NIST SP 800-59 a National Security System is a system that its function, operation, or use must fulfil some of the following criteria. CHOOSE ALL THAT APPLY. Response:

Per NIST SP 800-59, an information system whose function, operation, or use involves intelligence activities is designated as a National Security System. This criterion is fundamental to safeguarding national security information and processes.

NIST SP 800-59 defines a National Security System as one that involves cryptologic activities related to national security. Such systems are critical for protecting sensitive communications and classified information.

Information systems that involve the command and control of military forces are explicitly identified as National Security Systems in NIST SP 800-59. These systems are essential for military operations and national defense.

Systems involving equipment that is an integral part of a weapon or weapons system also fall under the definition of a National Security System by NIST SP 800-59. This ensures the security of critical defense infrastructure.