Who is responsible for command and control over assigned and attached postal platoons?

The correct choice is Postal Operations Command, as this entity is specifically designated to oversee the command and control of assigned and attached postal platoons within the Army. The role of Postal Operations Command is central to maintaining effective postal services, ensuring that they meet operational requirements and standards. This includes the management of postal resources and coordination of postal support in various operational environments.

Postal Operations Command is tasked with the logistical aspects of postal operations, which encompasses the movement, processing, and delivery of mail. By providing this focused command structure, it allows postal platoons to function efficiently, ensuring that service members receive timely communication from home and can send correspondence efficiently as well.

The other options, while related to Army operations, do not hold the specific responsibility for postal platoons. Human Resources Command oversees personnel management but not the operational command of postal units. Army Logistics Command deals with broader logistics and supply operations rather than focusing solely on postal functions. Army Personnel Command, likewise, focuses on personnel aspects without direct oversight of postal operations. Thus, Postal Operations Command is uniquely positioned to fulfill the needs and responsibilities concerning postal platoons.