The S-4 is primarily responsible for which of the following?

The S-4 is primarily responsible for logistics and supply within an organization, particularly in a military context. This role focuses on the planning, procurement, and distribution of supplies, equipment, and services required for the effective functioning of the unit. The S-4 ensures that all logistical needs are met, which includes managing inventory, coordinating transportation, and overseeing the supply chain. This is crucial for maintaining operational readiness and supporting training activities.

By contrast, the other areas of responsibility mentioned involve different aspects of a unit's operation. Information and security pertain more to the management of data and personnel safety, while administrative duties relate to the management of documents, personnel records, and policy compliance. Operations and training primarily focus on the execution of missions and the preparation of personnel for those missions. Each of these functions is essential to the overall success of the unit, but they fall under different specialties separate from logistics and supply.