What term refers to an extension of the USPS that operates military postal facilities?

The term that refers to an extension of the United States Postal Service (USPS) operating military postal facilities is known as the Military Postal Service. This service is specifically designed to support the postal needs of military personnel and their families, ensuring that mail can be delivered to and from remote and combat areas where traditional postal services may not be available or reliable. The Military Postal Service plays a critical role in maintaining communication for service members, which is vital for their morale and connection to home.

In contrast, the other terms like Official Mail Center, Mail Control Activity, and Aerial Mail Terminals refer to different aspects or types of postal operations. The Official Mail Center deals with managing and processing official government mail, while Mail Control Activities involve tracking and managing the flow of mail within a specific organization. Aerial Mail Terminals focus on facilitating air transport of mail. These functions serve important roles but do not encompass the specific mission and framework of the Military Postal Service.