How did business change from 1840 to 1900 in the passage nine to five

Two of these describe "federalism." (choose two answers) select one or more: a. the national government absolutely controls all state governments. b. power is shared by the national and state governments. c. state governments exercise absolute power over the national government. d. it is a compromise meant to eliminate the disadvantages of a "unitary" and a "confederate" system.