The U.S. Navy is part of the Department of Defense, which oversees all military branches. Other options include departments focused on land management, commerce, and transportation, which do not pertain to military services. Therefore, the correct answer is A. Defense. ;
The U.S. Navy is part of the Department of Defense, which oversees all military branches in the United States. The Navy's functions are essential for national security, unlike the other listed departments that handle different governmental responsibilities. The correct answer is option A. Defense.
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