Which of these resulted from the supreme court's ruling in brown v. board of education (1954)? a. a series of rulings on plans to bus students to desegregate city school systems b. a follow-up ruling allowing states to amend their constitutions to allow segregation c. an order to the federal government to take action guaranteeing that states obeyed its ruling d. an increase in the amount of federal money sent to the states to operate their public schools