Final answer:
The FOS for Company ABC would primarily contact their assigned Industrial Security Representative for DSS-related matters under the NISP.
Step-by-step explanation:
As the Facility Security Officer (FOS) for Company ABC involved with the National Industrial Security Program (NISP), your primary contact for the Defense Security Service (DSS) would typically be the assigned Industrial Security Representative.
This person is responsible for overseeing the protection of classified information at defense contractor facilities within their jurisdiction.
It is your responsibility as a FOS to coordinate with this representative on security matters, ensure compliance with all relevant security guidelines and regulations, and address any concerns that arise in the course of executing your duties.