The correct options are: "Federal troops were allowed to enforce federal laws within state borders. - The Constitution, as a creation of the people, applied in all cases to all states."
In 1832 the theory of nullity could be put to the test during the so-called Nullification Crisis, after the state legislature of South Carolina approved an ordinance declaring federal taxes null. The current tax laws, strongly protectionist, clearly favored the industry and manufacturing interests of the north, to the detriment of the agricultural economy of the south, which is why South Carolina declared the tariff decree unconstitutional.
In response to this attitude, the Federal Congress passed a law known as the "Force Hill", by which authorized President Jackson the use of force if necessary, to enforce federal laws. In use of these faculties the president sent a force of warships of the Navy of the United States to the port of Charleston. Given these facts the state legislature revoked the law of nullity. The tensions in any case fell when both parties reached a tariff commitment for 1833 proposed by Henry Clay, to the satisfaction of Calhoun who then served in the Senate.
