What was john c. calhoun's theory of nullification? a. a state has the ability to nullify another state's law if that state finds another state's law unconstitutional. b. a state has the ability to nullify a federal law and therefore ignore that law, if that state finds the federal law unconstitutional. c. the federal government has the ability to nullify a state law if the supreme court finds the law unconstitutional. d. the federal government is constitutionally permitted to take up arms against any state that tries to nullify a federal law.