The correct answer is B) Coast Guard. The Coast Guard is responsible for the documentation and naming of vessels in the United States. Per federal regulations, a change in a documented vessel's name can only be made with the approval and authorization of the U.S. Coast Guard. The Commissioner of Customs, the Treasury Department, and the American Bureau of Shipping do not have the authority to approve name changes for documented vessels - that power rests solely with the Coast Guard as the agency responsible for vessel documentation and registration.