"we are unanimously of opinion that the law passed by the legislature of maryland, imposing a tax on the bank of the united states, is unconstitutional and void... this is a tax on the operation of an instrument employed by the government of the union to carry its powers into execution. such a tax must be unconstitutional..."

this decision of the supreme court upheld the principle that:

a. the federal and state governments are equal
b. congress has only powers specifically enumerated in the constitution
c. congress has the power to make laws to carry out its constitutional duties
d. the federal government alone can levy taxes