Suppose that for health reasons, the government of the nation of Ironia wants to increase the amount of broccoli citizens consume. Which of the following policies could be used to achieve the goal?
a. A price floor to support broccoli growers.
b. A price ceiling to ensure that broccoli remains affordable to consumers.
c. A subsidy paid to shoppers who buy broccoli.
d. A subsidy paid to farmers who grow broccoli.