<P> 15 . To provide for calling forth the militia to execute the laws of the union, suppress insurrections and repel invasions; </P> <P> 16 . To provide for organizing, arming, and disciplining, the militia, and for governing such part of them as may be employed in the service of the United States, reserving to the states respectively, the appointment of the officers, and the authority of training the militia according to the discipline prescribed by Congress; </P> <P> 17 . To exercise exclusive legislation in all cases whatsoever, over such District (not exceeding ten miles (16 km) square) as may, by cession of particular states, and the acceptance of Congress, become the seat of the government of the United States, and to exercise like authority over all places purchased by the consent of the legislature of the state in which the same shall be, for the erection of forts, magazines, arsenals, dockyards, and other needful buildings . </P> <P> Other congressional powers have been granted, or confirmed, by constitutional amendments . The Thirteenth (1865), Fourteenth (1868), and Fifteenth Amendments (1870) gave Congress authority to enact legislation to enforce rights of all citizens regardless of race, including voting rights, due process, and equal protection under the law . Generally militia forces are controlled by state governments, not Congress . </P>

Which of the following is an example of a tax congress has the power to levy