Which of the following denotes a system related to command and control in the Army?

The choice that denotes a system related to command and control in the Army is the Global Command and Control System - Army (GCCS-A). This system is designed specifically to support military operations by providing commanders with a comprehensive picture of the battlefield. It facilitates the collection, analysis, and dissemination of critical operational data, enabling effective decision-making and coordination among various units and commands.

GCCS-A integrates information from multiple sources, allowing for real-time situational awareness, which is essential in fast-paced military environments. It serves as a vital tool for enhancing communication and interoperability among diverse military branches and allied forces, reflecting the importance of command and control in modern military operations.

The other options, while they may relate to information systems in some capacity, do not specifically refer to a command and control system within the Army context. Data Deployment Services and Digital Tactical Support System may pertain to different aspects of military logistics and tactical operations, but they do not encompass the overarching command and control functions that GCCS-A provides.