Which organization is responsible for the design, acquisition, and single systems management of the Defense Switched Network?

The Defense Information Systems Agency (DISA) is the organization responsible for the design, acquisition, and single systems management of the Defense Switched Network (DSN). DISA's role is critical as it manages the overall infrastructure, ensuring that the network supports the Department of Defense (DoD) in providing secure and reliable communication channels.

This organization is tasked with maintaining the integrity and security of the communication framework while also managing acquisition processes that allow for upgrades and expansions to the network. As the unified command responsible for delivering joint command and control capabilities, DISA plays a pivotal role in supporting military operations.

Other organizations mentioned in the options serve different roles. For example, the Defense Logistics Agency focuses on logistics and supply chain management, whereas the Communications Squadron typically handles local communications tasks rather than overarching network management. The Air Force Communications Agency, although involved in communications, does not have the full scope of responsibilities for the DSN that DISA has.