Which military command is responsible for managing transportation matters regarding military supplies to foreign nations?

The correct answer emphasizes the role of the US Air Force's Air Mobility Command (AMC) in managing transportation concerning military supplies to foreign nations. AMC is specifically tasked with providing strategic air mobility for the Department of Defense, which includes the transportation of personnel and cargo to support military operations globally. This command ensures effective movement across the air domain, thereby directly impacting logistics and support for alliances and foreign military partnerships.

The other options pertain to different aspects of military logistics and transportation but do not specifically focus on the air movement of supplies. For instance, the US Military Surface Deployment and Distribution Command (SDDC) primarily manages surface transportation and distribution, rather than aerial logistics. The Defense Logistics Agency (DLA) coordinates logistics support and supplies but does not solely cover transportation matters. Lastly, the US Navy's Military Sealift Command (MSC) specializes in maritime logistics and sealift capabilities, which may involve transporting goods but are not focused on air mobility, as conducted by the AMC.