Which office administers the NISP on behalf of the Department of Defense (DoD)?

The Defense Security Service (DSS) is the correct answer because it is the agency responsible for administering the National Industrial Security Program (NISP) on behalf of the Department of Defense (DoD). DSS provides a range of services that include oversight of security clearances, protecting classified information, and ensuring that contractors comply with security regulations in their operations related to national defense.

DSS also plays a critical role in providing guidance and support to industrial partners, assisting them in establishing and maintaining security programs that adhere to federal policies. This encompasses conducting security inspections, evaluating the security systems of contractors, and offering training and resources to enhance their security measures. Their mission is focused on safeguarding national security interests through effective management of industrial security.

The other options provided are not involved in administering the NISP directly. The Defense Security Office (DSO) and the Department of Defense Security Agency (DODSA) are not recognized as agencies that oversee industrial security matters in the same way as DSS. The National Security Office (NSO) does not exist under the framework of the DoD's organizational structure as it pertains to industrial security as defined by NISP. Thus, DSS is the designated organization carrying out these critical functions for the DoD.